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  • 51.
    Gel'mukhanov, Faris
    et al.
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Plashkevych, O.
    Ågren, Hans
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Anisotropic EXAFS measured in the Raman mode: a way to determine bond angles in randomly oriented species2001Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics, ISSN 0953-4075, E-ISSN 1361-6455, Vol. 34, nr 5, s. 869-879Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is shown that, contrary to the case of ordinary EXAFS measurements, EXAFS measured in the Raman mode is polarization sensitive for randomly oriented systems. This fact can be used to predict bond angles and gives an opportunity for a complete structural determination of gaseous or amorphous systems.

  • 52.
    Gel'mukhanov, Faris
    et al.
    KTH, Tidigare Institutioner, Bioteknologi.
    Privalov, Timofei
    KTH, Tidigare Institutioner, Kemi.
    Ågren, Hans
    KTH, Tidigare Institutioner, Bioteknologi.
    Temperature dependence and Debye-Waller factors for resonant x-ray Raman scattering in solids2000Ingår i: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, Vol. 62, nr 21, s. 13996-14005Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Resonant x-ray Raman scattering is a strongly coherent process. The well defined phase relations between scattering channels through the core excited states localized at different atoms result in a conservation of the electronic crystal momentum. However, as we show here, the zero-point and thermal vibrations dephase these scattering channels and lead to incoherent contributions with different spectral shapes. The relative strength of the coherent and incoherent contributions are found to strongly depend on temperature via a Debye-Waller factor. This results in a characteristic temperature dependence of the spectral profile of the resonant x-ray Raman scattering.

  • 53.
    Gel'mukhanov, Faris
    et al.
    KTH, Tidigare Institutioner, Bioteknologi.
    Salek, Pawel
    KTH, Tidigare Institutioner, Bioteknologi.
    Shalagin, A
    Ågren, Hans
    KTH, Tidigare Institutioner, Bioteknologi.
    X-ray Raman scattering under pulsed excitation2000Ingår i: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 112, nr 13, s. 5593-5603Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Accounting for actual and anticipated developments in synchrotron radiation- and in x-ray and free electron laser techniques, we present a theory of resonant scattering of short-pulsed x rays. Both the instantaneous and integrated-over-observation-time x-ray scattering spectra are studied. Contrary to the commonly accepted notion of an instantaneous probability, we find that the correct quantity describing the resonant x-ray scattering (RXS) experiment is the probability integrated over the time of measurement. It is shown that the integral RXS probability is given by the convolution of the RXS probability for monochromatic excitation with the Wiener-Khintchine spectrum of the nonstationary incident radiation. We have found that short pulses yield a new spectral band following a non-Raman dispersion law. The finite duration of pulses results in a broadening of the Raman resonance. Some aspects of the theoretical analysis of the RXS spectra as functions of the pulse duration time are analyzed by numerical calculations.

  • 54.
    Gel'mukhanov, Faris
    et al.
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Salek, Pawel
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Ågren, Hans
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Vibrationally resolved core-photoelectron spectroscopy as an infinite-slit interferometry2001Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 64, nr 1Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    During a molecular vibration, an atom changes continuously its position. Just as the emitted photoelectron waves, the electromagnetic waves absorbed by the atom in the different positions are strictly coherent and have different well-defined phases. These phases depend on the relation between the instantaneous internuclear distance and the photoelectron, respectively, photon wavelengths. We predict that the interference of these coherent waves strongly influences the vibrational profile of the photoelectron spectra of core electrons in a molecule. This effect increases with increasing x-ray photon frequency and results in a deformation and broadening of the vibrational profile. In the case of surface adsorbed molecules, the vibrational profile depends strongly on the direction of the photoelectron ejection and photon momentum, and the orientational sensitivity of a vibrational profile can even be used as a tool to define the orientation of adsorbed molecules.

  • 55.
    Gel’mukhanov, Faris
    et al.
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Sałek, Paweł
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Privalov, Timofei
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Ågren, Hans
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Duration of x-ray Raman scattering1999Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 59, nr 1, s. 380-389Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There has recently been much interest in using the notion of a duration time to analyze resonant x-ray Raman scattering (RXS) of atoms, molecules, and solids. This notion implies a selection of processes with different time scales responsible for the formation x-ray Raman spectra, and has been useful for actual predictions of various phenomena associated with RXS and that subsequently have been experimentally verified. However, the notion of a duration time for the x-ray scattering event can also have some paradoxical consequences, as when comparing the RXS duration with the relaxation time of the wave packet evolution in the case when the inverse detuning of the excitation energy is shorter than the time of flight or the lifetime of the core excited state. We present here a solution of this contradiction and give a detailed analysis of the notion of the duration time for RXS. It is shown that this time is complex and consists of two qualitatively different contributions. The first originates in the irreversible decay of the core excited state, while the imaginary part is caused by a reversible dephasing in the time domain. We investigate also the evolution of the wave packets of bound and dissociative states to stationary distributions. The theoretical analysis is accompanied by numerical examples of the time evolution of the wave packet in bound and dissociative core excited states of the N2 and HCl molecules.

  • 56.
    Gel'mukhanov, Faris
    et al.
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Ågren, Hans
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Salek, Pawel
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Doppler effects in resonant x-ray Raman scattering1998Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 57, nr 4, s. 2511-2526Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Theory for Doppler effects in resonant x-ray Raman scattering (RXS) is presented. It is shown that the "electron" Doppler effect is important in nonradiative RXS for decay transitions between continuum nuclear states lying above the dissociation threshold, and that the averaging of the RXS cross section over molecular orientations can lead to strong non-lorentzian broadenings of the atomiclike resonances. The Doppler effect is found to give a unique possibility to distinguish dissociating identical atoms, because different peaks correspond to atoms with opposite Doppler shifts. Spectral features of the atomiclike profile are predicted and analyzed. Strong oscillations of the RXS cross section will occur as a consequence of the interference of the Auger electrons. Due to the Doppler effect and the interference, the atomiclike profile can be associated with supernarrow spectral features, the width of which goes below the lifetime broadening and is practically independent of the spectral distribution of the incident radiation. As another consequence of the oscillations and strong anisotropy caused by the interference, we predict parity selection rules for Auger decay transitions in both bound and dissociative systems. The corresponding experiments can be realized by measurements of resonant Auger of surface adsorbed molecules and for molecules by the electron-ion coincidence technique.

  • 57.
    Guimaraes, Freddy Fernandes
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Gelmukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Pump-probe spectroscopy of molecules driven by infrared field in both ground and excited electronic states2006Ingår i: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 125, nr 20, artikel-id 204313Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pump-probe spectra of molecules driven by strong infrared (IR) field in both ground and excited states are studied theoretically. The role of the final state interaction becomes important when pump and probe pulses overlap, and the Rabi frequency is comparable with the lifetime broadening of the excited state and the duration of the pump pulse. Our theoretical approach is applied to x-ray absorption of nitrogen molecule and valence photoionization of carbon monoxide. It is shown that IR-x-ray pump-probe spectroscopy can directly evidence the delocalization of core hole.

  • 58.
    Guimaraes, Freddy Fernandes
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Gelmukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Cesar, A.
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Quantum wave packet revivals in IR plus X-ray pump-probe spectroscopy2005Ingår i: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 405, nr 4-6, s. 398-403Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The wave packet revivals constitute a central concept of X-ray spectroscopy with ultra-high spectral resolution. The revival phenomenon allows to resolve the anharmonical shift or rotational structure by means of time dependent measurements and makes X-ray pump-probe spectroscopy a powerful technique to study long-term dynamics of molecules in different phases. We study the revivals referring to the X-ray absorption spectrum of the NO molecule driven by strong infrared pulse. It is shown that the phase sensitive trajectories of the center of gravity of the wave packets and the X-ray spectra copy each other.

  • 59.
    Guimaraes, Freddy Fernandes
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Kimberg, Victor
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Felicissimo, Viviane C.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Gelmukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Cesar, A.
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Infrared–x-ray pump-probe spectroscopy of the NO molecule2005Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 72, nr 1, artikel-id 012714Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Two color infrared-x-ray pump-probe spectroscopy of the NO molecule is studied theoretically and numerically in order to obtain a deeper insight of the underlying physics and of the potential of this suggested technology. From the theoretical investigation a number of conclusions could be drawn: It is found that the phase of the infrared field strongly influences the trajectory of the nuclear wave packet, and hence, the x-ray spectrum. The trajectory experiences fast oscillations with the vibrational frequency with a modulation due to the anharmonicity of the potential. The dependences of the x-ray spectra on the delay time, the duration, and the shape of the pulses are studied in detail. It is shown that the x-ray spectrum keep memory about the infrared phase after the pump field left the system. This memory effect is sensitive to the time of switching-off the pump field and the Rabi frequency. The phase effect takes maximum value when the duration of the x-ray pulse is one-fourth of the infrared field period, and can be enhanced by a proper control of the duration and intensity of the pump pulse. The manifestation of the phase is different for oriented and disordered molecules and depends strongly on the intensity of the pump radiation.

  • 60.
    Guimaraes, Freddy Fernandes
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Kimberg, Victor
    KTH, Skolan för bioteknologi (BIO).
    Felicissimo, Viviane C.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Cesar, A.
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Phase sensitive x-ray absorption driven by strong infrared fields2005Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 71, nr 4, artikel-id 043407Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper it is demonstrated that electron vibrational absorption of molecules driven by strong IR field provides rich physical interpretations of dynamical processes on a short time scale. The phase of an infrared field influences strongly the trajectory of the nuclear wave packet and the probing spectrum. It is shown that the probe spectrum keeps memory of the infrared phase even after that the pump field left the system. The phase effect takes maximum value when the duration of the probe pulse is of the order of the infrared field period, and can be enhanced by a proper control of the duration and intensity of the pump pulse. The phase effect is different for oriented and disordered molecules and depends strongly on the intensity of pump radiation. It can be an effective tool to study charge transfer processes like proton transfer in hydrogen bonded networks.

  • 61.
    Guimaraes, Freddy
    et al.
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Kimberg, Vikctor
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Gel'mukhanov, Faris
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Ågren, Hans
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Two-color phase-sensitive x-ray pump-probe spectroscopy2004Ingår i: Phys. Rev. A, ISSN 1050-2947, Vol. 70, s. 062504-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    X-ray pump-probe spectroscopy is studied theoretically. It is shown that two-color-optical+x-ray-excitation with constant phase of the pump radiation exhibits strong interference between the one- and two-photon excitation channels. This effect is found to be large for both long and short pump pulses, while the interference vanishes for x-ray pulses longer than one cycle of the pump field. It is predicted that the spectral shape of x-ray absorption is strongly influenced by the absolute phase of the pump light. A strong sensitivity of the x-ray absorption and/or photoionization profile to the phase and detuning of the pump field is predicted, as well as to the duration of the x-ray pulse. Our simulations display oscillations of x-ray absorption as a function of the delay time. This effect allows the synchronization of the x-ray pulse relative to the "comb" of the pump radiation. The interference pattern copies the temporal and space distribution of the pump field. We pay special attention to the role of molecular orientation for the interference effect.

  • 62.
    Hennies, F.
    et al.
    Institut für Experimentalphysik, Universität Hamburg.
    Polyutov, Sergey
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Minkov, Ivaylo
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Pietzsch, A.
    Institut für Experimentalphysik, Universität Hamburg.
    Nagasono, M.
    Institut für Experimentalphysik, Universität Hamburg.
    Gel'Mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Triguero, L.
    Piancastelli, M-N
    Department of Physics, Uppsala University.
    Wurth, W.
    Institut für Experimentalphysik, Universität Hamburg.
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Föhlisch, A.
    Institut für Experimentalphysik, Universität Hamburg.
    Non-Adiabatic effects in Resonant Inelastic x-ray Scattering2005Ingår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 95, nr 16, s. 163002-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We have studied the spectral features of resonant inelastic x-ray scattering of condensed ethylene with vibrational selectivity both experimentally and theoretically. Purely vibrational spectral loss features and coupled electronic and vibrational losses are observed. The one-step theory for resonant soft x-ray scattering is applied, taking multiple vibrational modes and vibronic coupling into account. Our investigation of ethylene underlines that the assignment of spectral features observed in resonant inelastic x-ray scattering of polyatomic systems requires an explicit description of the coupled electronic and vibrational loss features.

  • 63.
    Hennies, F.
    et al.
    Institut für Experimentalphysik, Universität Hamburg.
    Polyutov, Sergey
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Minkov, Ivaylo
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Pietzsch, A.
    Institut für Experimentalphysik, Universität Hamburg.
    Nagasono, M.
    Institut für Experimentalphysik, Universität Hamburg.
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Triguero, L.
    Piancastelli, M. N.
    Department of Physics, Uppsala University.
    Wurth, W.
    Institut für Experimentalphysik, Universität Hamburg.
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Föhlisch, A.
    Institut für Experimentalphysik, Universität Hamburg.
    Dynamic interpretation of resonant x-ray Raman scattering: ethylene and benzene2007Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 76, nr 3, s. 032505-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present a dynamic interpretation of resonant x-ray Raman scattering where vibrationally selective excitation into molecular resonances has been employed in comparison with excitation into higher lying continuum states for condensed ethylene and benzene as molecular model systems. In order to describe the purely vibrational spectral loss features and coupled electronic and vibrational losses the one-step theory for resonant soft x-ray scattering is applied, taking multiple vibrational modes and vibronic coupling into account. The scattering profile is found to be strongly excitation energy dependent and to reflect the intermediate states dynamics of the scattering process. In particular, the purely vibrational loss features allow one to map the electronic ground state potential energy surface in light of the excited state dynamics. Our study of ethylene and benzene underlines the necessity of an explicit description of the coupled electronic and vibrational loss features for the assignment of spectral features observed in resonant x-ray Raman scattering at polyatomic systems, which can be done in both a time independent and a time dependent picture. The possibility to probe ground state vibrational properties opens a perspective to future applications of this photon-in-photon-out spectroscopy.

  • 64.
    Hikosaka, Y.
    et al.
    UVSOR Facility, Institute for Molecular Science, Okazaki .
    Velkov, Yasen
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Shigemasa, E.
    UVSOR Facility, Institute for Molecular Science, Okazaki .
    Kaneyasu, T.
    UVSOR Facility, Institute for Molecular Science, Okazaki .
    Tamenori, Y.
    Japan Synchrotron Radiation Research Institute, Sayo.
    Liu, Ji-Cai
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    X-ray absorption measured in the resonant Auger scattering mode2008Ingår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, nr 7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report both experimental and theoretical studies on x-ray absorption measured in the resonant Auger scattering mode of gas phase carbon monoxide near the O1s -> 2 pi region. Both experiment and theory display a crucial difference between the x-ray absorption profiles obtained in the conventional and resonant scattering modes. Lifetime vibrational interference is the main source of the difference. It is demonstrated that such interference, which arises from a coherent excitation to overlapping intermediate levels, ruins the idea for obtaining x-ray absorption spectra in a lifetime broadening free regime.

  • 65.
    Ignatova, Nina
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi. Siberian Federal University.
    da Cruz, Vinícius V.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Couto, Rafael C.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Ertan, Emelie
    Stockholm university.
    Odelius, Michael
    Stockholm university.
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Guimarães, Freddy F.
    Zimin, Andrei
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi. Siberian Federal University.
    Polyutov, Sergey
    Siberian Federal University.
    Gel’mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Kimberg, Victor
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Infrared-pump–x-ray-probe spectroscopy of vibrationally excited molecules2017Ingår i: Physical Review A, ISSN 2469-9926, Vol. 95, nr 4, artikel-id 042502Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We develop a theory of infrared (IR)-pump–x-ray-probe spectroscopy for molecular studies. We illustrate advantages of the proposed scheme by means of numerical simulations employing a vibrational wave packet technique applied to x-ray absorption and resonant inelastic x-ray scattering (RIXS) spectra of the water molecule vibrationally excited by a preceding IR field. The promotion of the vibrationally excited molecule to the dissociative 1a−114a1 and bound 1a−112b2 core-excited states with qualitatively different shapes of the potential energy surfaces creates nuclear wave packets localized along and between the OH bonds, respectively. The projection of these wave packets on the final vibrational states, governed by selection and propensity rules, results in spatial selectivity of RIXS sensitive to the initial vibrationally excited state, which makes it possible to probe selectively the ground state properties along different modes. In addition, we propose to use RIXS as a tool to study x-ray absorption from a selected vibrational level of the ground state when the spectral resolution is sufficiently high to resolve vibrational overtones. The proposed technique has potential applications for advanced mapping of multidimensional potential energy surfaces of ground and core-excited molecular states, for symmetry-resolved spectroscopy, and for steering chemical reactions.

  • 66.
    Ignatova, Nina
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Teoretisk kemi och biologi. Siberian Federal University.
    V. Cruz, Vinícius
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Couto, Rafael C.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Ertan, Emelie
    Zimin, Andrey
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    F. Guimarães, Freddy
    Polyutov, Sergey
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Kimberg, Victor
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Odelius, Michael
    Gel’mukhanov, Faris
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Teoretisk kemi och biologi.
    Gradual collapse of nuclear wave functions regulated by frequency tuned X-ray scattering2017Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, nr 43891Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    As is well established, the symmetry breaking by isotope substitution in the water molecule results in localisation of the vibrations along one of the two bonds in the ground state. In this study we find that this localisation may be broken in excited electronic states. Contrary to the ground state, the stretching vibrations of HDO are delocalised in the bound core-excited state in spite of the mass difference between hydrogen and deuterium. The reason for this effect can be traced to the narrow “canyon-like” shape of the potential of the state along the symmetric stretching mode, which dominates over the localisation mass-difference effect. In contrast, the localisation of nuclear motion to one of the HDO bonds is preserved in the dissociative core-excited state . The dynamics of the delocalisation of nuclear motion in these core-excited states is studied using resonant inelastic X-ray scattering of the vibrationally excited HDO molecule. The results shed light on the process of a wave function collapse. After core-excitation into the state of HDO the initial wave packet collapses gradually, rather than instantaneously, to a single vibrational eigenstate.

  • 67. Journel, L.
    et al.
    Guillemin, R.
    Stolte, W. C.
    Carniato, S.
    Taieb, R.
    Minkov, I.
    Gel'mukhanov, Faris
    KTH.
    Salek, P.
    Ågren, Hans
    KTH.
    Hudson, A.
    Lindle, D. W.
    Simon, M.
    Ultrafast nuclear motion in Cl 1s core-excited HCl and DCl probed by resonant inelastic X-ray scattering: Experiment and theory2007Ingår i: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 156, s. XLIV-XLIVArtikel i tidskrift (Övrigt vetenskapligt)
  • 68. Kikas, A.
    et al.
    Kaambre, T.
    Saar, A.
    Kooser, K.
    Nommiste, E.
    Martinson, I.
    Kimberg, Victor
    KTH, Tidigare Institutioner, Kemi.
    Polyutov, Sergey
    KTH, Tidigare Institutioner, Kemi.
    Gel'mukhanov, Faris
    KTH, Tidigare Institutioner, Bioteknologi.
    Resonant inelastic x-ray scattering at the F 1s photoabsorption edge in LiF: Interplay of excitonic and conduction states, and Stokes' doubling2004Ingår i: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 70, nr 8Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The excitation-decay processes at the F 1s photoabsorption edge in LiF crystal are studied using resonant inelastic x-ray scattering spectroscopy. The Raman-type linear dispersion and the narrowing of the x-ray fluorescence peak are observed at resonant excitation. A theoretical model based on the Kramers-Heisenberg formula describes well the main features in fluorescence spectra and allows one to separate the contributions of the exciton and the conduction states in the scattering spectra. At the same time, the role of the shape of the spectral distribution within the incident radiation is emphasized as being critically sensitive to the number, kind, and onset of the spectral features which finally appear in the scattering spectra at a particular incident photon energy, particularly in the subthreshold excitation region.

  • 69. Kimberg, V.
    et al.
    Lindblad, A.
    Soederstroem, J.
    Travnikova, O.
    Nicolas, C.
    Sun, Yuping
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Kosugi, N.
    Miron, C.
    Single-Molecule X-Ray Interferometry: Controlling Coupled Electron-Nuclear Quantum Dynamics and Imaging Molecular Potentials by Ultrahigh-Resolution Resonant Photoemission and Ab Initio Calculations2013Ingår i: Physical Review X, ISSN 2160-3308, E-ISSN 2160-3308, Vol. 3, nr 1, artikel-id 011017Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper reports an advanced study of the excited ionic states of the gas-phase nitrogen molecule in the binding-energy region of 22-34 eV, combining ultrahigh-resolution resonant photoemission (RPE) and ab initio configuration-interaction calculations. The RPE spectra are recorded for nine photon energies within the N 1s -> pi* absorption resonance of N-2 by using a photon bandwidth that is considerably smaller than lifetime broadening, and the dependence on excitation energy of the decay spectra is analyzed and used for the first assignment of 12 highly overlapped molecular states. The effect on the RPE profile of avoided curve crossings between the final N-2(+) ionic states is discussed, based on theoretical simulations that account for vibronic coupling, and compared with the experimental data. By use of synchrotron radiation with high spectral brightness, it is possible to selectively promote the molecule to highly excited vibrational sublevels of a core-excited electronic state, thereby controlling the spatial distribution of the vibrational wave packets, and to accurately image the ionic molecular potentials. In addition, the mapping of the vibrational wave functions of the core-excited states using the bound final states with far-from-equilibrium bond lengths has been achieved experimentally for the first time. Theoretical analysis has revealed the rich femtosecond nuclear dynamics underlying the mapping phenomenon. DOI: 10.1103/PhysRevX.3.011017

  • 70.
    Kimberg, Victor
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Gelmukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Angular anisotropy of the delay time of short pulses in impurity band based photonic crystals2005Ingår i: Journal of Optics. A, Pure and applied optics, ISSN 1464-4258, E-ISSN 1741-3567, Vol. 7, nr 3, s. 118-122Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigate the transmission of short pulses through one-dimensional impurity band based photonic crystals. We found a strong dependence of the delay time on the angle of incidence. The delay time is larger for larger incident angles for the transverse electrical mode, while the delay time of the transverse magnetic mode has a qualitatively different angular dependence, especially in the region below the Brewster angle. The strong anisotropy of the delay time is traced to the anisotropy of the group velocity which is directly related to the angular dependence of the impurity band structure.

  • 71.
    Kimberg, Victor
    et al.
    KTH, Tidigare Institutioner, Bioteknologi.
    Gelmukhanov, Faris
    KTH, Tidigare Institutioner, Bioteknologi.
    Ågren, Hans
    KTH, Tidigare Institutioner, Bioteknologi.
    Pent, E.
    Plekhanov, A.
    Kuchin, I.
    Rodionov, M.
    Shelkovnikov, V.
    Angular properties of band structures in one-dimensional holographic photonic crystals2004Ingår i: Journal of Optics. A, Pure and applied optics, ISSN 1464-4258, E-ISSN 1741-3567, Vol. 6, nr 10, s. 991-996Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    One-dimensional photonic crystals with continuous distribution of the dielectric constant were fabricated by the use of photopolymer materials and laser holography. The angular dependence of light propagation through the system was studied experimentally and theoretically. It is shown that the Brewster angles for different bands are different, in contrast to the conventional two-layer Bragg reflector with a step-like distribution of the dielectric constant. Comparison of the theory with experimental data allowed us to define the parameters of the hologram-the dielectric contrast and the shrinkage of the structure.

  • 72.
    Kimberg, Victor
    et al.
    KTH, Skolan för bioteknologi (BIO).
    Guimaraes, Freddy Fernandes
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Felicissimo, Viviane C.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Phase-sensitive wave-packet dynamics caused by a breakdown of the rotating-wave approximation2006Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 73, nr 2, artikel-id 023409Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The water dimer driven by strong infrared field is studied in the two-vibrational mode approximation. A pump pulse excites the OH vibrational modes and creates a coherent superposition of vibrational states of the low-frequency OO mode. The solution of the Schrodinger equation in the adiabatic approximation shows a strong sensitivity of the OO vibrational wave-packet dynamics to the absolute phase of the pump field. This effect appears due to a break down of the rotating-wave approximation when the Rabi frequency of the OH vibrational transition approaches the frequency of the OH mode. The violation of the rotating wave approximation modifies considerably the interaction of the probe radiation with the laser-driven molecule.

  • 73. Kimberg, Victor
    et al.
    Kosugi, Nobuhiro
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Theoretical studies of angle-resolved ion yield spectra of core-to-valence transitions of acetylene2009Ingår i: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 130, nr 11Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recent experimental results on angle-resolved photoion-yield spectroscopy (ARPIS) spectra near the core-to-valence excitation in acetylene show significant anisotropies in the spectral profile measured at 0 degrees and 90 degrees regarding to the polarization direction of x-ray photons. In the present work, a theoretical model is proposed to simulate the fine structure and anisotropy in ARPIS. This employs two-dimensional potential energy surfaces of the ground and core-excited states, as well as transition dipole moments, including symmetric and antisymmetric bending modes to account for Duschinsky effect. The ARPIS is simulated by evaluation of the ion flux, which is found as a projection of the excited state wave packet on a particular direction in the molecular frame. Numerical simulations explain qualitatively the angular dependence of the experimental spectra of the 1s -> 1 pi(*)(g) and 1s -> 3 sigma(*)(u) transitions. The effects of the lifetime of the core-excited state, the direction of the ion flux, and the transition dipole moment are discussed.

  • 74.
    Kimberg, Victor
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Polyutov, Sergey
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Baev, Alexander
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Zheng, Q.D.
    Institute for Lasers, Photonics and Biophotonics, State University of New York at Buffalo.
    He, G. S.
    Institute for Lasers, Photonics and Biophotonics, State University of New York at Buffalo.
    Dynamics of cavityless lasing generated by ultrafast multiphoton excitation2006Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 74, nr 3, artikel-id 033814Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A dynamical theory is developed with the purpose of explaining recent experimental results on multiphoton-excited amplified stimulated emission (ASE). Several conspicuous features of this experiment are analyzed, like the threshold dependence of the spectral profile on the pump intensity, and spectral shifts of the ASE pulses co- and counterpropagating relative to the pump pulse. Two models are proposed and evaluated, one based on the isolated molecule and another which involves solvent interaction. The spectral shift between the forward and backward ASE pulses arises in the first model through the competition between the ASE transitions from the pumped vibrational levels and from the bottom of the excited-state well, while in the solvent-related model the dynamical solute-solvent interaction leads to a relaxed excited state, producing an additional ASE channel. In the latter model the additional redshifted ASE channel makes the dynamics of ASE essentially different from that in the molecular model because the formation of the relaxed state takes a longer time. The variation of the pump intensity influences strongly the relative intensities of the different ASE channels and, hence, the spectral shape of ASE in both models. The regime of ASE changes character when the pump intensity crosses a threshold value. Such a phase transition occurs when the ASE rate approaches the rate of vibrational relaxation or the rate of solute-solvent relaxation in the first excited state.

  • 75. Kitajima, M.
    et al.
    Ueda, K.
    De Fanis, A.
    Furuta, T.
    Shindo, H.
    Tanaka, H.
    Okada, K.
    Feifel, R.
    Sorensen, S. L.
    Gel'mukhanov, Faris
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Baev, A.
    Ågren, Hans
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Doppler effect in resonant photoemission from SF6: Correlation between doppler profile and auger emission anisotropy2003Ingår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 91, nr 21Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Fragmentation of the SF6 molecule upon F 1s excitation has been studied by resonant photoemission. The F atomiclike Auger line exhibits the characteristic Doppler profile that depends on the direction of the photoelectron momentum relative to the polarization vector of the radiation as well as on the photon energy. The measured Doppler profiles are analyzed by the model simulation that takes account of the anisotropy of the Auger emission in the molecular frame. The Auger anisotropy extracted from the data decreases with an increase in the F-SF5 internuclear distance.

  • 76. Lindblad, Andreas
    et al.
    Kimberg, V
    Söderström, Johan
    Nicolas, C
    Travnikova, O
    Kosugi, N
    Gel’mukhanov, Faris
    Miron, C
    Vibrational scattering anisotropy in O2 -- €”dynamics beyond the Born–Oppenheimer approximation2012Ingår i: New Journal of Physics, ISSN 1367-2630, E-ISSN 1367-2630, Vol. 14, nr 11Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Born–Oppenheimer and Franck–Condon approximations are two major concepts in the interpretation of electronic excitations and modeling of spectroscopic data in the gas and condensed phases. We report large variations of the anisotropy parameter (β) for the fully resolved vibrational sub-states of the X2Πg electronic ground state of O+2 populated by participator resonant Auger decay following excitations of K-shell electrons into the σ☆ resonance by monochromatic x-rays. Decay spectra for light polarization directions parallel and perpendicular to the electron detection axis recorded at four different excitation energies in the vicinity of the O 1s → σ☆ transition are presented. Breakdown of the Born–Oppenheimer approximation is for the first time selectively observed for the lower vibrational sub-states, where two quantum paths—resonant and direct—leading to the same final cationic state exist. The higher vibrational sub-states can only be populated by resonant photoemission; hence no interference between these channels can occur.

  • 77.
    Liu, Ji-Cai
    et al.
    North China Elect Power Univ, Dept Math & Phys, Beijing 102206, Peoples R China.;Shandong Normal Univ, Collaborat Innovat Ctr Light Manipulat & Applicat, Jinan 250358, Shandong, Peoples R China..
    da Cruz, Vinicius Vaz
    Univ Potsdam, Inst Phys & Astron, Karl Liebknecht Str 24-25, D-14476 Potsdam, Germany..
    Polyutov, Sergey
    Siberian Fed Univ, Krasnoyarsk 660041, Russia.;Fed Res Ctr KSC SB RAS, Kirensky Inst Phys, Krasnoyarsk 660036, Russia..
    Foehlisch, Alexander
    Univ Potsdam, Inst Phys & Astron, Karl Liebknecht Str 24-25, D-14476 Potsdam, Germany.;Helmholtz Zentrum Berlin Mat & Energie, Inst Methods & Instrumentat Synchrotron Radiat Re, Albert Einstein Str 15, D-12489 Berlin, Germany..
    Gel'mukhanov, Faris
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Teoretisk kemi och biologi. Siberian Fed Univ, Krasnoyarsk 660041, Russia;Fed Res Ctr KSC SB RAS, Kirensky Inst Phys, Krasnoyarsk 660036, Russia.
    Recoil-induced dissociation in hard-x-ray photoionization2019Ingår i: Physical Review A: covering atomic, molecular, and optical physics and quantum information, ISSN 2469-9926, E-ISSN 2469-9934, Vol. 100, nr 5, artikel-id 053408Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We predict the recoil-induced molecular dissociation in hard-x-ray photoionization. The recoil effect is caused by electronic and photon momentum exchange with the molecule. We show the strong role of relativistic effects for the studied molecular fragmentation. The recoil-induced fragmentation of the molecule is caused by elongation of the bond due to the vibrational recoil effect and because of the centrifugal force caused by the rotational recoil. The calculations of the x-ray photoelectron spectra of the H-2 and NO molecules show that the predicted effects can be observed in high-energy synchrotrons like SOLEIL, SPring-8, PETRA, and XFEL SACLA. The relativistic effect enhances the recoil momentum transfer and makes it strongly sensitive to the direction of ejection of the fast photoelectron with respect to the photon momentum.

  • 78.
    Liu, Ji-Cai
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Felicissimo, Viviane Costa
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Guimarães, Freddy Fernandes
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Wang, Chuankui
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Gelmukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Coherent control of population and pulse propagation beyond the rotating wave approximation2008Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics, ISSN 0953-4075, E-ISSN 1361-6455, Vol. 41, nr 7, artikel-id 074016Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The dynamics of populations of the vibrational states in a NO molecule ( one-photon absorption) and of the electronic states in a 4,4'-bis( dimethylamino) stilbene molecule ( two-photon absorption) is studied versus the frequency, intensity and shape of the laser pulse. We show that specially designed infrared laser pulses can build selective populations of certain vibrational states. A detuning of light frequency from the vibrational resonance qualitatively changes the dynamics of populations. It is found out that the populations of the nonresonant levels follow the pulse shape adiabatically if the detuning significantly exceeds the inverse characteristic time of the change of the pulse. Depopulation of the nonresonant vibrational states leads to a high population of the resonant state at the end of the pulse. Complete breakdown of the standard rotating wave approximation for a two-photon absorption process is observed even for a rather small intensity of the laser pulse. An analytical solution for the interaction of a pulse with a three-level system beyond the rotating wave approximation is obtained, and it is in close agreement with the strict numerical solution of the amplitude equations. Special attention is paid to the population dynamics of randomly oriented molecules. The orientational disorder as well as the vibrations limit the coherent population transfer. Calculations show the strong role of the anisotropy of photoexcitation in the coherent control of populations which can affect the anisotropy of photobleaching.

  • 79.
    Liu, Ji-Cai
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Gelmukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Wang, Chuan-Kui
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Dynamics of cooperative emissions in a cascade three-level molecular system driven by an ultrashort laser pulse2008Ingår i: Chinese Physics (Beijing), ISSN 1009-1963, E-ISSN 1741-4199, Vol. 17, nr 11, s. 4211-4217Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper investigates the dynamics of cooperative emissions in a cascade three-level system driven by an ultras short laser pulse by solving numerically the full-wave Maxwell-Bloch equations. The 4, 40-bis(dimethylamino) stilbene molecule is used as the model molecule because of its strong two-photon absorption property. The two-colour cooperative emissions are studied as functions of molecular number density and dephasing rate of the dipole coherence. The propagation effects on the evolution of the cooperative radiations are also taken into account. The cooperative radiations are enhanced for large number density of the molecule, while the fast dephasing of the dipole coherence reduces the intensity of the cooperative radiations and delays the emission times or even inhibits the formation of the emissions. The delay time of the radiation decreases with the increase of the molecular number density and the propagation distance.

  • 80.
    Liu, Ji-Cai
    et al.
    North China Elect Power Univ, Dept Math & Phys, Beijing 102206, Peoples R China.;Shandong Normal Univ, Collaborat Innovat Ctr Light Manipulat & Applicat, Jinan 250358, Shandong, Peoples R China..
    Miron, Catalin
    Synchrotron SOLEIL, Boite Postale 48, F-91192 Gif Sur Yvette, France.;Horia Hulubei Natl Inst Phys & Nucl Engn, ELI NP, 30 Reactorului St, RO-077125 Magurele, Judet Ilfov, Romania.;Univ Paris Saclay, CEA Saclay, CNRS, LIDYL,CEA, F-91191 Gif Sur Yvette, France..
    Ågren, Hans
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Teoretisk kemi och biologi.
    Polyutov, Sergey
    Siberian Fed Univ, Krasnoyarsk 660041, Russia.;Fed Res Ctr KSC SB RAS, Kirensky Inst Phys, Krasnoyarsk 660036, Russia..
    Gel'mukhanov, Faris
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Teoretisk kemi och biologi.
    Resonant x-ray second-harmonic generation in atomic gases2019Ingår i: Physical Review A: covering atomic, molecular, and optical physics and quantum information, ISSN 2469-9926, E-ISSN 2469-9934, Vol. 100, nr 6, artikel-id 063403Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We explore the x-ray second-harmonic generation process induced by resonant two-photon absorption in systems with inversion symmetry. We show that this process becomes allowed in the x-ray region due to nondipole contributions. It is found that, although a plane-wave pump field generates only a longitudinal second-harmonic field, a Gaussian pump beam creates also a radially polarized transverse second-harmonic field which is stronger than the longitudinal one. Contrary to the longitudinal component, the transverse second-harmonic field with zero intensity on the axis of the pump beam can run in free space. Our theory is applied to Ar and Ne atomic vapors and predicts an energy conversion efficiency of x-ray second-harmonic generation of 3.2 x 10(-11) and 1.3 x 10(-12), respectively.

  • 81.
    Liu, Ji-Cai
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Nicolas, Christophe
    Sun, Yu-Ping
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Flammini, Roberto
    O'Keeffe, Patrick
    Avaldi, Lorenzo
    Morin, Paul
    Kimberg, Victor
    Kosugi, Nobuhiro
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Miron, Catalin
    Multimode Resonant Auger Scattering from the Ethene Molecule2011Ingår i: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 115, nr 18, s. 5103-5112Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Resonant Auger spectra of ethene molecule have been measured with vibrational resolution at several excitation energies in the region of the C1s(-1)1b(2g)(π*) resonance. The main features observed in the experiment have been assigned and are accurately interpreted on the basis of ab initio multimode calculations. Theory explains the extended vibrational distribution of the resonant Auger spectra and its evolution as a function of the excitation energy by multimode excitation during the scattering process. As a result, the resonant Auger spectra display two qualitatively different spectral features following the Raman and non-Raman dispersion laws, respectively. Calculations show that two observed thresholds of formation of non-Raman spectral bands are related to the "double-edge" structure of the X-ray absorption spectrum.

  • 82.
    Liu, Jicai
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Nicolas, P
    Morin, V
    Kimberg, Victor
    KTH, Skolan för bioteknologi (BIO).
    Kosugi, N
    Gelmukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Multimode resonant Auger scattering from the ethylene moleculeManuskript (preprint) (Övrigt vetenskapligt)
  • 83.
    Liu, Jicai
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Sun, Yu-Ping
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Wang, Chuankui
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Gelmukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Auger effect in the presence of strong x-ray pulses2010Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, ISSN 1050-2947, Vol. 81, nr 4, s. 043412-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We study the role of propagation of strong x-ray free-electron laser pulses on the Auger effect. When the system is exposed to a strong x-ray pulse the stimulated emission starts to compete with the Auger decay. As an illustration we present numerical results for Ar gas with the frequency of the incident x-ray pulse tuned in the 2p(3/2)-4s resonance. It is shown that the pulse propagation is accompanied by two channels of amplified spontaneous emission, 4s-2p(3/2) and 3s-2p(3/2), which reshape the pulse when the system is inverted. The population inversion is quenched for longer propagation distances where lasing without inversion enhances the Stokes component. The results of simulations show that the propagation of the strong x-ray pulses affect intensively the Auger branching ratio.

  • 84.
    Liu, Ji-Cai
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Velkov, Yasen
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Rinkevicius, Zilvinas
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Resonant inelastic X-ray Raman scattering induced by Rabi flopping of core holes 2008Ingår i: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 453, nr 1-3, s. 117-121Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new scheme of X-ray pump-probe experiment is suggested in this Letter, namely resonant inelastic X-ray scattering accompanied by core-hole hopping induced by a strong laser field. In particular, we study the dynamics of X-ray Raman scattering of N-2 molecules in a strong IR field. The laser-induced mixing of the core holes of opposite parities opens symmetry forbidden scattering channels. The strength of the symmetry forbidden channels strongly depends on the interrelationship between the time of Rabi flopping of the core holes and the scattering duration or the duration of the X-ray pulse.

  • 85.
    Liu, Ji-Cai
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Velkov, Yasen
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Rinkevicius, Zilvinas
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Gel`mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Symmetry-forbidden x-ray Raman scattering induced by a strong infrared-laser field2008Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 77, nr 4, s. 043405-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Resonant inelastic x-ray scattering accompanied by core-hole hopping induced by a strong infrared-laser field is studied for the nitrogen molecule. This process involves a strong laser-field-induced promotion of ungerade core holes created by a weak x-ray pulse to a gerade core level, which opens symmetry-forbidden scattering channels and gives rise to new features in the x-ray scattering spectrum. The core-hole hopping within the short lifetime of the core-excited state required for observation of the described process can be achieved at moderate intensities of the infrared field (similar to 10(12) W/cm(2)) because of the large transition dipole moment between the relevant core levels. The dynamics of resonant inelastic x-ray scattering assisted by change of core-hole parity is studied in detail versus the intensity, detuning, phase, and duration of the incident infrared-laser and x-ray pulses.

  • 86.
    Liu, Ji-Cai
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Wang, Chuan-Kui
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Gelmukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Dynamics of multilevel molecules and pulse propagation beyond rotating wave approximation near two-photon resonance2007Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 76, nr 4, artikel-id 043422Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Dynamics of multilevel molecules and pulse propagation is studied near the two-photon resonance. We have found a strict solution of this problem beyond the rotating wave approximation. Our analytical solution is in close agreement with the strict numerical solution for the 4,4(')-bis(dimethylamino) stilbene molecule. The compensation of the dynamical Stark shift is studied for fixed-in-space molecules. It is shown that the orientational disorder does not allow complete compensation of the dynamical Stark shift.

  • 87.
    Liu, Ji-Cai
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Wang, Chuan-Kui
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Gelmukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Optical limiting of short laser pulses2007Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 76, nr 053804Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The dynamics of pulse propagation accompanied by harmonic generation, stimulated Raman scattering, amplified spontaneous emission, and superfluorescence is studied near the two-photon resonance. We explore the optical limiting of intense and short laser pulses. The numerical solutions of the coupled Bloch and Maxwell's equations for the 4,4(')-bis(dimethylamino) stilbene molecule are compared with the two-photon area theorem. It is shown that the area theorem explains qualitatively the major dynamical properties of pulse propagation even if the propagation is accompanied by the generation of new fields. In agreement with the area theorem, we see that the conventional dependence of the transmittance on the propagation depth is not valid for intense pulses.

  • 88. Liu, X. J.
    et al.
    Cherepkov, N. A.
    Semenov, S. K.
    Kimberg, V.
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Prumper, G.
    Lischke, T.
    Tanaka, T.
    Hoshino, M.
    Tanaka, H.
    Ueda, K.
    Young's double-slit experiment using core-level photoemission from N-2: revisiting Cohen-Fano's two-centre interference phenomenon2006Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics, ISSN 0953-4075, E-ISSN 1361-6455, Vol. 39, nr 23, s. 4801-4817Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The core-level photoelectron spectra of N-2 molecules are observed at high energy resolution, resolving the 1 sigma(g) and 1 sigma(u) components as well as the vibrational components in the extended energy region from the threshold up to 1 keV. The sigma(g)/sigma(u) cross section ratios display modulation as a function of photoelectron momentum due to the two-centre interference, analogous to the classical Young's double-slit experiment, as predicted by Cohen and Fano a long time ago. The Cohen-Fano interference modulations display different phases depending on the vibrational excitations in the core-ionized state. Extensive ab initio calculations have been performed within the Hartree-Fock and random phase approximations in prolate spheroidal coordinates. The dependence of photoionization amplitudes on the vibrational states was taken into account using the Born-Oppenheimer approximation. The ab initio results are in reasonable agreement with the experimental data. The theoretical analysis allows the modulation to be connected with the onset of transitions to the states of increasing orbital angular momentum which occurs at increasing photon energies. Deviation from the Cohen-Fano formula is found for both the experimental and the ab initio results and is attributed to electron scattering by the neighbouring atom. A new formula for the interference modulation is derived within the framework of the multiple scattering technique. It differs from the classical Cohen-Fano formula by the addition of twice the scattering phase of the photoelectron by the neighbouring atom. We demonstrate that one can measure directly the scattering phase by fitting our formula to the experimental results.

  • 89. Liu, X. -J
    et al.
    Miao, Quan
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Gelmukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Patanen, M.
    Travnikova, O.
    Nicolas, C.
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Ueda, K.
    Miron, C.
    Einstein-Bohr recoiling double-slit gedanken experiment performed at the molecular level2015Ingår i: XXIX INTERNATIONAL CONFERENCE ON PHOTONIC, ELECTRONIC, AND ATOMIC COLLISIONS (ICPEAC2015), PTS 1-12, Institute of Physics Publishing (IOPP), 2015, artikel-id UNSP 112063Konferensbidrag (Refereegranskat)
    Abstract [en]

    Double-slit experiments illustrate proof for wave-particle complementarity. The essence of Einstein-Bohr's debate about wave-particle duality was whether the momentum transfer between a particle and a recoiling slit could mark the path, thus destroying the interference. We realized this recoiling double-slit gedanken experiment by resonant X-ray photoemission from molecular oxygen for geometries near equilibrium (coupled slits) and in a dissociative state far away from equilibrium (decoupled slits). Interference is observed in the former case, while the electron momentum transfer quenches the interference in the latter case.

  • 90. Liu, X. J.
    et al.
    Prumper, G.
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi (stängd 20110512).
    Cherepkov, N. A.
    Tanaka, H.
    Ueda, K.
    Young's double-slit experiment using two-center core-level photoemission: Photoelectron scattering effects2007Ingår i: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 156, s. 73-77Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Core-level photoemission from N-2 can be considered as an analogue of Young's double-slit experiment (YDSE) in which the double-slit is replaced by a pair of N 1s orbitals. N 1s photoelectron spectra of N-2 are measured in the extended photon energy region up to similar to 1 keV at unprecedented resolution. The measured ratio between the 1 sigma(g) and 1 sigma(u) photoionization cross-sections oscillates as a function of electron momentum due to interference effects analogue to YDSE. We found a shift of the interference pattern with respect to a prediction by a simple model for coherent two-center emission, the Cohen-Fano formula, and attributed it to photoelectron scattering by the neighboring atom. We demonstrate that the shift can be used to determine the scattering phase of the photoelectron.

  • 91. Liu, Xiao-Jing
    et al.
    Miao, Quan
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi. Shandong University of Science and Technology, China .
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi. Synchrotron SOLEIL, France .
    Patanen, Minna
    Travnikova, Oksana
    Nicolas, Christophe
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Ueda, Kiyoshi
    Miron, Catalin
    Einstein-Bohr recoiling double-slit gedanken experiment performed at the molecular level2015Ingår i: Nature Photonics, ISSN 1749-4885, E-ISSN 1749-4893, Vol. 9, nr 2, s. 120-125Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Double-slit experiments illustrate the quintessential proof for wave-particle complementarity. If information is missing about which slit the particle has traversed, the particle, behaving as a wave, passes simultaneously through both slits. This wave-like behaviour and corresponding interference is absent if 'which-slit' information exists. The essence of Einstein-Bohr's debate about wave-particle duality was whether the momentum transfer between a particle and a recoiling slit could mark the path, thus destroying the interference. To measure the recoil of a slit, the slits should move independently. We showcase a materialization of this recoiling double-slit gedanken experiment by resonant X-ray photoemission from molecular oxygen for geometries near equilibrium (coupled slits) and in a dissociative state far away from equilibrium (decoupled slits). Interference is observed in the former case, while the electron momentum transfer quenches the interference in the latter case owing to Doppler labelling of the counter-propagating atomic slits, in full agreement with Bohr's complementarity.

  • 92. Liu, Xiao-Jing
    et al.
    Miao, Quan
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Patanen, Minna
    Travnikova, Oksana
    Nicolas, Christophe
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Ueda, Kiyoshi
    Miron, Catalin
    Symmetry breaking by site-dependent momentum exchangeIngår i: Nature Physics, ISSN 1745-2473, E-ISSN 1745-2481, ISSN 1745-2473Artikel i tidskrift (Övrigt vetenskapligt)
  • 93. Marchenko, T.
    et al.
    Carniato, S.
    Journel, L.
    Guillemin, R.
    Kawerk, E.
    Zitnik, M.
    Kavcic, M.
    Bucar, K.
    Bohinc, R.
    Petric, M.
    da Cruz, V. Vaz
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Gel'mukhanov, F.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Simon, M.
    Electron Dynamics in the Core-Excited CS2 Molecule Revealed through Resonant Inelastic X-Ray Scattering Spectroscopy2015Ingår i: Physical Review X, ISSN 2160-3308, E-ISSN 2160-3308, Vol. 5, nr 3, artikel-id 031021Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present an experimental and theoretical study of resonant inelastic x-ray scattering (RIXS) in the carbon disulphide CS 2 molecule near the sulfur K-absorption edge. We observe a strong evolution of the RIXS spectral profile with the excitation energy tuned below the lowest unoccupied molecular orbital (LUMO) absorption resonance. The reason for this is twofold. Reducing the photon energy in the vicinity of the LUMO absorption resonance leads to a relative suppression of the LUMO contribution with respect to the emission signal from the higher unoccupied molecular orbitals, which results in the modulation of the total RIXS profile. At even larger negative photon-energy detuning from the resonance, the excitation-energy dependence of the RIXS profile is dominated by the onset of electron dynamics triggered by a coherent excitation of multiple electronic states. Furthermore, our study demonstrates that in the hard x-ray regime, localization of the S 1s core hole occurs in CS2 during the RIXS process because of the orientational dephasing of interference between the waves scattering on the two sulfur atoms. Core-hole localization leads to violation of the symmetry selection rules for the electron transitions observed in the spectra.

  • 94. Marchenko, T.
    et al.
    Goldsztejn, G.
    Jankala, K.
    Travnikova, O.
    Journel, L.
    Guillemin, R.
    Sisourat, N.
    Ceolin, D.
    Zitnik, M.
    Kavcic, M.
    Bucar, K.
    Mihelic, A.
    de Miranda, B. Cunha
    Ismail, I.
    Lago, A. F.
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi. Institute of Nanotechnology, Spectroscopy and Quantum Chemistry, Siberian Federal University, 660041 Krasnoyarsk, Russia.
    Puettner, R.
    Piancastelli, M. N.
    Simon, M.
    Potential Energy Surface Reconstruction and Lifetime Determination of Molecular Double-Core-Hole States in the Hard X-Ray Regime2017Ingår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 119, nr 13, artikel-id 133001Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A combination of resonant inelastic x-ray scattering and resonant Auger spectroscopy provides complementary information on the dynamic response of resonantly excited molecules. This is exemplified for CH3I, for which we reconstruct the potential energy surface of the dissociative I 3d(-2) double-core-hole state and determine its lifetime. The proposed method holds a strong potential for monitoring the hard x-ray induced electron and nuclear dynamic response of core-excited molecules containing heavy elements, where ab initio calculations of potential energy surfaces and lifetimes remain challenging.

  • 95. Marehenko, T.
    et al.
    Carniato, S.
    Journel, L.
    Guillemin, R.
    Kawerk, E.
    Zitnik, M.
    Kavcic, M.
    Bucar, K.
    Bohinc, R.
    Petric, M.
    da Cruz, V. Vaz
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Gelmukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Simon, M.
    Electron dynamics in the core-excited CS2 molecule revealed through resonant inelastic x-ray scattering spectroscopy2015Ingår i: XXIX INTERNATIONAL CONFERENCE ON PHOTONIC, ELECTRONIC, AND ATOMIC COLLISIONS (ICPEAC2015), PTS 1-12, Institute of Physics Publishing (IOPP), 2015, artikel-id UNSP 112012Konferensbidrag (Refereegranskat)
    Abstract [en]

    We present an experimental and theoretical study of resonant inelastic x-ray scattering (RIXS) in the CS2 molecule near the S 1s edge. We show that localization of the S 1s core-hole occurs in CS2 during the RIXS process due to the orientational dephasing of interference between the waves scattering on the two sulfur atoms. Strong evolution of the RIXS profile with the excitation energy far below the first absorption resonance reflects the onset of electron dynamics triggered by a coherent excitation of multiple electronic states.

  • 96.
    Miao, Quan
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Ding, Hong-Juan
    Sun, Yu-Ping
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Wang, Chuan-Kui
    Numerical analysis on optical limiting performance of a series of phthalocyanines for nanosecond pulses2012Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics, ISSN 0953-4075, E-ISSN 1361-6455, Vol. 45, nr 8, s. 085402-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The optical limiting properties of a series of peripherally substituted phthalocyanines with different central metals and axial chloride ligand for nanosecond pulses have been studied by solving numerically the two-dimensional paraxial field equation together with the rate equations using the Crank-Nicholson method. It is shown that all of these compounds exhibit good optical limiting behaviour, and phthalocyanines with heavier central metals have better optical limiting performance due to the faster intersystem crossing caused by the enhanced spin-orbit coupling. The major mechanism of optical limiting for long pulses is the sequential (singlet-singlet)x( triplet-triplet) nonlinear absorption. Dynamics of populations is characterized mainly by the effective transfer time of the population from the ground state to the lowest triplet state. The long lifetime of the triplet state is important but not determinant. In addition, the performance of optical limiting strongly depends on the thickness and concentration of the absorber.

  • 97.
    Miao, Quan
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Liu, J. -C
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Rubensson, J. -E
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Dissociative X-ray Lasing2012Ingår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 109, nr 23, s. 233905-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    X-ray lasing is predicted to ensue when molecules are pumped into dissociative core-excited states by a free-electron-laser pulse. The lasing is due to the population inversion created in the neutral dissociation product, and the process features self-trapping of the x-ray pulse at the gain ridge. Simulations performed for the HCl molecule pumped at the 2p(1/2) -> 6 sigma resonance demonstrate that the scheme can be used to create ultrashort coherent x-ray pulses.

  • 98.
    Miao, Quan
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Travnikova, Oksana
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Kimberg, Victor
    Sun, Yu-Ping
    Thomas, T. Darrah
    Nicolas, Christophe
    Patanen, Minna
    Miron, Catalin
    Rotational Doppler effect: a probe for molecular anisotropyManuskript (preprint) (Övrigt vetenskapligt)
  • 99.
    Miao, Quan
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi. Shandong University of Science and Technology, China.
    Travnikova, Oksana
    Gel'mukhanov, Faris
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi. Synchrotron SOLEIL, L'Orme des Merisiers, France.
    Kimberg, Victor
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi. Synchrotron SOLEIL, L'Orme des Merisiers, France.
    Sun, Yu-Ping
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi. Shandong University of Technology, China.
    Thomas, T. Darrah
    Nicolas, Christophe
    Patanen, Minna
    Miron, Catalin
    Rotational Doppler Effect: A Probe for Molecular Orbitals Anisotropy2015Ingår i: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 6, nr 9, s. 1568-1572Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The vibrationally resolved X-ray photoelectron spectra of X-2 Sigma(+)(g)(3 sigma(-1)(g)) and B-2 Sigma(+)(u)(2 sigma(-1)(u)) states of N-2(+) were recorded for different photon energies and orientations of the polarization vector. Clear dependencies of the spectral line widths on the X-ray polarization as well as on the symmetry of the final electronic states are observed. Contrary to the translational Doppler, the rotational Doppler broadening is sensitive to the photoelectron emission anisotropy. On the basis of theoretical modeling, we suggest that the different rotational Doppler broadenings observed for gerade and ungerade final states result from a Young's double-slit interference phenomenon.

  • 100.
    Minkov, Ivaylo
    et al.
    KTH, Tidigare Institutioner, Bioteknologi.
    Gelmukhanov, Faris
    KTH, Tidigare Institutioner, Bioteknologi.
    Friedlein, R.
    Osikowicz, W.
    Suess, C.
    Örhvall, G
    Sorensen, S.L.
    Braun, S.
    Murdey, R.
    Salaneck, W.R.
    Ågren, Hans
    KTH, Tidigare Institutioner, Bioteknologi.
    Core-excitations of naphthalene: Vibrational structure versus chemical shifts2004Ingår i: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 121, nr 12, s. 5733-5739Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The initial state chemical shifts and vibrational fine structure of core excitations of naphthalene were analyzed using high-resolution x-ray photoelectron emission (XPS) and near-edge x-ray absorption fine structure (NEXAFS) spectra. The carbon atoms at peripheral sites were found to experience a small chemical shift and exhibit similar charge-vibrational coupling. The C-H stretching modes provide significant contributions to overall shape of spectra in the XPS spectra. The results show that vibrational fine structure dominates by particular C-C stretching modes, and in XPS of C2 and C3 sites also by high-energy C-H stretching modes.

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