Change search
Refine search result
1 - 21 of 21
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Chang, J.
    et al.
    Månsson, Martin
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Pailhes, S.
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Lipscombe, O. J.
    Hayden, S. M.
    Patthey, L.
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Mesot, J.
    Anisotropic breakdown of Fermi liquid quasiparticle excitations in overdoped La2-xSrxCuO42013In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 4, p. 2559-Article in journal (Refereed)
    Abstract [en]

    High-temperature superconductivity emerges from an un-conventional metallic state. This has stimulated strong efforts to understand exactly how Fermi liquids breakdown and evolve into an un-conventional metal. A fundamental question is how Fermi liquid quasiparticle excitations break down in momentum space. Here we show, using angle-resolved photoemission spectroscopy, that the Fermi liquid quasiparticle excitations of the overdoped superconducting cuprate La1.77Sr0.23CuO4 is highly anisotropic in momentum space. The quasiparticle scattering and residue behave differently along the Fermi surface and hence the Kadowaki-Wood's relation is not obeyed. This kind of Fermi liquid breakdown may apply to a wide range of strongly correlated metal systems where spin fluctuations are present.

  • 2.
    Chang, Johan
    et al.
    Laboratory for Neutron Scattering, ETH Zurich and Paul Scherrer Institute, Villigen.
    Pailhés, Stephane
    Laboratory for Neutron Scattering, ETH Zurich and Paul Scherrer Institute, Villigen.
    Shi, Ming
    Swiss Light Source, Paul Scherrer Institute, Villigen.
    Månsson, Martin
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Voigt, Jörg
    Institute for Solid State Research, Forschungszentrum Jülich.
    Perez, V.
    Swiss Light Source, Paul Scherrer Institute, Villigen.
    Patthey, Luc
    Swiss Light Source, Paul Scherrer Institute, Villigen.
    Momono, Naoki
    Department of Physics, Hokkaido University, Sapporo.
    Oda, Migaku
    Department of Physics, Hokkaido University, Sapporo.
    Ido, Masayuki
    Department of Physics, Hokkaido University, Sapporo.
    Schnyder, A.
    Condensed Matter Theory Group, Villigen.
    Mudry, C.
    Condensed Matter Theory Group, Villigen.
    Mesot, Joël
    Laboratory for Neutron Scattering, ETH Zurich and Paul Scherrer Institute, Villigen.
    When low- and high-energy electronic responses meet in cuprate superconductors2007In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 75, no 22, p. 224508-Article in journal (Refereed)
    Abstract [en]

    The existence of coherent quasiparticles near the Fermi energy in the low-temperature state of high-temperature superconductors has been well established by angle-resolved photoemission spectroscopy (ARPES). We present a study of La1.83Sr0.17CuO4 in the superconducting state and report an abrupt change in the quasiparticle spectral function, as we follow the dispersion of the ARPES signal from the Fermi energy to 0.6 eV. The interruption in the quasiparticle dispersion separates coherent quasiparticle peaks at low energies from broad incoherent excitations at high energies. We find that the boundary between these low-energy and high-energy features exhibits a cosine-shaped momentum dependence, reminiscent of the superconducting d-wave gap. Further intriguing similarities between characteristics of the incoherent excitations and quasiparticle properties suggest a close relation between the electronic response at high and low energies in cuprate superconductors.

  • 3.
    Chang, Johan
    et al.
    Laboratory for Neutron Scattering, ETH Zurich, Paul Scherrer Institute, Villigen.
    Shi, Ming
    Swiss Light Source, Paul Scherrer Institute, Villigen.
    Pailhés, Stephane
    Laboratory for Neutron Scattering, ETH Zurich, Paul Scherrer Institute, Villigen.
    Månsson, Martin
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Bendounan, Azzedin
    Laboratory for Neutron Scattering, ETH Zurich, Paul Scherrer Institute, Villigen.
    Sassa, Yasmine
    Laboratory for Neutron Scattering, ETH Zurich, Paul Scherrer Institute, Villigen.
    Patthey, Luc
    Swiss Light Source, Paul Scherrer Institute, Villigen.
    Momono, Naoki
    Department of Physics, Hokkaido University, Sapporo.
    Oda, Migaku
    Department of Physics, Hokkaido University, Sapporo.
    Ido, Masayuki
    Department of Physics, Hokkaido University, Sapporo.
    Guerrero, S.
    Condensed Matter Theory Group, Paul Scherrer Institute, Villigen.
    Mudry, C.
    Condensed Matter Theory Group, Paul Scherrer Institute, Villigen.
    Mesot, Joël
    Laboratory for Neutron Scattering, ETH Zurich, Paul Scherrer Institute, Villigen.
    Anisotropic quasiparticle scattering rates in slightly underdoped to optimally doped high-temperature La2-xSrxCuO4 superconductors2008In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 78, no 20, p. 205103-Article in journal (Refereed)
    Abstract [en]

    An angle-resolved photoemission study of the scattering rate in the superconducting phase of the high-temperature superconductor La2-xSrxCuO4 with x=0.145 and x=0.17, as a function of binding energy and momentum, is presented. We observe that the scattering rate scales linearly with binding energy up to the high-energy scale E-1 similar to 0.4 eV. The scattering rate is found to be strongly anisotropic, with a minimum along the (0,0)-(pi,pi) direction. A possible connection to a quantum-critical point is discussed.

  • 4.
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT), Material Physics, Material Physics, MF.
    Investigations of Transition Metal Systems: Angle-Resolved Photoelectron Spectroscopy at Low and High Energy2007Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    The work presented in this thesis aims at achieving an increased understanding of the electronic structure of materials whose properties are to a large extent governed by transition metals. All studies are based on data from angle-resolved photoelectron spectroscopy (ARPES) employed on the valence band of the studied systems. In some cases spectroscopic data have also been combined with numerical electronic structure studies performed using a density functional theory computer code.

    Five of the studies make extensive use of the benefits provided by performing angle-resolved photoelectron spectroscopy at high photon energies. When probed with soft x-ray photons, the near Fermi edge distribution of spectral weight in Nd2-xCexCuO4 and La2-x-yNdySrxCuO4 display significant differences as compared to similar studies performed in the 20-100 eV range of photon energies. This effect can be attributed to the approximate two-fold increase in probing depth as compared to the low photon energy case.

    However, high photon energies not only give increased probing depth, it also enables a straightforward interpretation of ARPES data from fully three-dimensional compounds in terms of valence band energy dispersion. This principle has been used to study the dispersions in the transition metal oxides CoO and Cu2O as well as in a proof-of-principle study, where copper was used as a test case.

    CoO exhibits a magnetic phase transition at the Néel temperature, from a paramagnetic state into an antiferromagnetically ordered state. The presented data show a significant shift of spectral weight between different band structure regions as the sample temperature is elevated across the Néel temperature.

    The Cu2O ARPES data have confirmed the existence of a hybridized Cu 3d - Cu 4s state. Through comparision with theoretically calculated results, a refined value of the Hubbard potential U has been determined.

    An extensive ARPES dataset from copper, covering the entire Brillouin zone, has in a proof-of-principle study been used to derive the binding-energy resolved valence band charge density.

    Two ARPES studies of the La2-x-yNdySrxCuO4 system have been performed in the cnventional low photon energy range. The high energy resolution has enabled a detailed study of dispersive features in the near Fermil level region of the valence band.

  • 5.
    Claesson, Thomas
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Månsson, Martin
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Dallera, Claudia
    INFM-Dipartimento di Fisica, Politecnico di Milano, Italy.
    Venturini, Federica
    Europ. Synchrt. Radiation Facility, Grenoble, France.
    De Nadaï, Celine
    Europ. Synchrt. Radiation Facility, Grenoble, France.
    Brookes, Nicholas B.
    Europ. Synchrt. Radiation Facility, Grenoble, France.
    Tjernberg, Oscar
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Angle Resolved Photoemission from Nd(1.85)Ce(0.15)CuO(4) using High Energy Photons: A Fermi Surface Investigation2004In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 93, no 13, p. 136402-1-136402-4Article in journal (Refereed)
    Abstract [en]

    We have performed an angle resolved photoemission study on a single crystal of the optimally electron doped (n-type) cuprate superconductor Nd2-xCexCuO4 (x=0.15) at a photon energy of 400 eV. The Fermi surface is mapped out and is, in agreement with earlier measurements, of hole-type with the expected Luttinger volume. However, comparing with previous low energy measurements, we observe a different Fermi surface shape and a different distribution of spectral intensity around the Fermi surface contour. The observed Fermi surface shape indicates a stronger electron correlation in the bulk as compared to the surface.

  • 6.
    Claesson, Thomas
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Månsson, Martin
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Finazzi, M.
    Dallera, C.
    Cezar, J. C.
    Brookes, N. B.
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Transfer of spectral weight across the magnetic transition in CoO: novel results from high-energy angle-resolved photoelectron spectroscopyManuscript (preprint) (Other academic)
  • 7.
    Claesson, Thomas
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Månsson, Martin
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Önsten, Anneli
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Shi, Ming
    Swiss Light Source, Paul Scherrer Institut, Switzerland.
    Sassa, Yasmine
    Laboratory for Neutron Scattering, Zürich, Paul Scherrer Institut.
    Pailhés, Stephane
    Laboratory for Neutron Scattering, Zürich, Paul Scherrer Institut.
    Chang, Johan
    Laboratory for Neutron Scattering, Zürich, Paul Scherrer Institut.
    Bendounan, Azzedin
    Synchrotron SOLEIL, L'Orme des Merisiers, France.
    Patthey, Luc
    Swiss Light Source, Paul Scherrer Institut, Switzerland.
    Mesot, Joël
    Paul Scherrer Institute, ETH Zürich, Switzerland.
    Muro, Takayuki
    Japan Synchrotron Radiation Research Institute.
    Matsushita, Tomohiro
    Japan Synchrotron Radiation Research Institute.
    Kinoshita, Toyohiko
    Japan Synchrotron Radiation Research Institute.
    Nakamura, Tetsuya
    Japan Synchrotron Radiation Research Institute.
    Momono, Naoki
    Department of Physics, Hokkaido University, Japan.
    Oda, Migaku
    Department of Physics, Hokkaido University, Japan.
    Ido, Masayuki
    Department of Physics, Hokkaido University, Japan.
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    The electronic structure of La(1.48)Nd(0.4)Sr(0.12)CuO(4) probed by high- and low-energy angle-resolved photoelectron spectroscopy: Evolution with probing depth2009In: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, Vol. 80, no 9, p. 094503-1-094503-6Article in journal (Refereed)
    Abstract [en]

    We present angle-resolved photoelectron spectroscopy data probing the electronic structure of the Nd-substituted high-T-c cuprate La1.48Nd0.4Sr0.12CuO4. Data have been acquired at low and high photon energies, h nu=55 and 500 eV, respectively. The two extracted Fermi surfaces show significant differences. The differences can be attributed to either the change in probing depth suggesting dissimilarity of the intrinsic electronic structure between surface and bulk regions, or a considerable c-axis dispersion signaling a strong interlayer coupling. At both photon energies, considerable spectral weight is observed at all points along the Fermi surface and the intensity distribution as well as Fermi-surface shape observed at low as well as high photon energy is markedly different from what has been previously reported for La1.28Nd0.6Sr0.12CuO4 by Zhou [Science 286, 268 (1999)]. Document Type: Article

  • 8.
    Grishin, Michael A.
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Månsson, Martin
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Tjernberg, Oscar
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Claesson, Thomas
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Karlsson, Henrik S.
    Optillion AB.
    Karlsson, Ulf O.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    A bandgap surface state at the GaSb(001) surface observed by femtosecond laser pump-and-probe photoemission spectroscopyManuscript (Other academic)
  • 9.
    Månsson, Martin
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT).
    Finazzi, Marco
    Dallera, Claudia
    De Nadaï, Celine
    Brookes, Nicholas B.
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT).
    Revealing the charge density in solidsManuscript (Other academic)
  • 10.
    Månsson, Martin
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT).
    Hayden, S. M.
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT).
    Chang, Johan
    Pailhés, Stephane
    Shi, Ming
    Mesot, Joël
    Patthey, Luc
    Momono, Naoki
    Oda, Migaku
    Ido, Masayuki
    Experimental evidence of a quantum phase transition in La(2-x)Sr(x)CuO4()Manuscript (Other academic)
  • 11.
    Månsson, Martin
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Karlsson, Ulf O.
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Pailhés, Stephane
    Laboratory for Neutron Scattering, ETH Zürich.
    Chang, Johan
    Laboratory for Neutron Scattering, ETH Zürich.
    Mesot, Joël
    Laboratory for Neutron Scattering, ETH Zürich.
    Shi, Ming
    Swiss Light Source, Paul Scherrer Institut, Villigen.
    Patthey, Luc
    Swiss Light Source, Paul Scherrer Institut, Villigen.
    Momono, Naoki
    Department of Physics, Hokkaido University, Sapporo.
    Oda, Migaku
    Department of Physics, Hokkaido University, Sapporo.
    Ido, Masayuki
    Department of Physics, Hokkaido University, Sapporo.
    On-board sample cleaver2007In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 78, no 7, p. 076103-Article in journal (Refereed)
    Abstract [en]

    An on-board sample cleaver has been developed in order to cleave small and hard-to-cleave samples. To acquire good cleaves from rigid samples the alignment of the cleaving blade with respect to the internal crystallographic planes is crucial. To have the opportunity to mount the sample and align it to the blade ex situ has many advantages. The design presented has allowed us to cleave very tiny and rigid samples, e.g., the high-temperature superconductor La(2-x)SrxCuO4. Further, in this design the sample and the cleaver will have the same temperature, allowing us to cleave and keep the sample at low temperature. This is a big advantage over prior cleaver systems. As a result, better surfaces and alignments can be realized, which considerably simplifies and improves the experiments.

  • 12.
    Månsson, Martin
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Grishin, Michael A.
    KTH, School of Information and Communication Technology (ICT), Material Physics (Closed 20120101).
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT), Material Physics (Closed 20120101).
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT), Material Physics (Closed 20120101).
    Karlsson, Henrik S.
    KTH, School of Information and Communication Technology (ICT), Material Physics (Closed 20120101).
    Karlsson, Ulf O.
    KTH, School of Information and Communication Technology (ICT), Material Physics (Closed 20120101).
    Electronic structure and electron dynamics at the GaSb(001) surface studied by femtosecond pump-and-probe pulsed laser photoemission spectroscopy2006In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 252, no 15, p. 5308-5311Article in journal (Refereed)
    Abstract [en]

    Transiently excited electron states at the GaSb(001) surface have been studied by means of time- and angle-resolved photoemission spectroscopy based on a femtosecond laser system. A normally unpopulated surface electron state has been found at similar to 250 meV above the valence band maximum with a strong confinement at the center of the surface Brillouin zone. The lifetime of transiently excited carriers at the intergap surface states has been found to be similar to 11 ps, associated with rapid carrier diffusion.

  • 13.
    Månsson, Martin
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Göthelid, Mats
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Grishin, Michael A.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Karlsson, Ulf O.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Ultrafast electron dynamics and recombination at the Ge(111): Sn(root 3 X root 3)R30 degrees surface2008In: Surface Science Letters, ISSN 0039-6028, Vol. 602, no 5, p. L33-L37Article in journal (Refereed)
    Abstract [en]

    We present the first study revealing the electronic structure and electron dynamics of the excited adatom state at the Ge(111): Sn(root 3 x root 3)R30 degrees surface. By the use of time- and angle-resolved photoemission spectroscopy, the normally unoccupied electronic structure of the partly empty Sn adatom can be probed. From the angle-resolved data we conclude that the adatom electrons at the Ge:Sn surface are more delocalized than at the clean Ge(111)c(2 x 8) surface. A unique pump-and-probe technique, based on a pulsed femtosecond laser-system, has also allowed us to study the recombination process of the excited state. We connect the recombination process of the excited electrons to the coherent fluctuations of the Sn adatoms. As a result we present an estimate for the time between each collective and coherent adatom flip Delta t = 9 ps, i.e. an adatom switching frequency nu(SW) approximate to 0.1 THz. We find that our results, contrary to scanning tunneling microscopy measurements [F. Ronci, S. Colonna, S.D. Thorpe, A. Cricenti, G. Le Lay, Phys. Rev. Lett. 95 (2005) 156101], agree very well with values extracted from molecular dynamics simulations found in the literature [J. Avila, A. Mascaraque, E.G. Michel, M.C. Asensio, G. Le Lay, J. Ortega, R. Perez, F. Flores, Phys. Rev. Lett. 82 (1999) 442; D. Farias, W. Kaminski, J. Lobo, J. Ortega, E. Hulpke, R. Perez, F. Flores, E.G. Michel, Phys. Rev. Lett. 91 (2003) 16103].

  • 14.
    Månsson, Martin
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Göthelid, Mats
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Grishin, Michael A.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Karlsson, Henrik S.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Le Lay, Guy
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Karlsson, Ulf O.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Electronic structure and electron dynamics of delocalized adatom states at the Ge(111)c(2 x 8) surfaceIn: Physical Review B, ISSN 1098-0121Article in journal (Refereed)
  • 15.
    Palmgren, Pål
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Önsten, Anneli
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Agnarsson, Björn
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Månsson, Martin
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Göthelid, Mats
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Band bending and structure dependent HOMO energy at the ZnO(0001)-titanyl phthalocyanine interface2007In: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 601, no 18, p. 4222-4226Article in journal (Refereed)
    Abstract [en]

    We have investigated the initial stages of titanyl phthalocyanine (TiOPc) growth on single crystalline ZnO(0 0 0 1). This organic-semiconductor interface is self-organizing as a 2 x 1 pattern appears in a low energy electron diffraction upon deposition of the molecules. To achieve this pattern, the TiOPc is suggested to adsorb standing with the edge of the molecule along the substrate atomic rows. Photoelectron spectroscopy is used to further analyze the interface; a relatively large upwards band bending amounting to 0.5 eV is found and a splitting of the molecules highest occupied molecular orbital occurs after thermal treatment, indicating that the molecules are lying down.

  • 16.
    Palmgren, Pål
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Szamota-Leandersson, Katolina
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Weissenrieder, Jonas
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Karlsson, Ulf O.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Göthelid, Mats
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Chemical reaction and interface formation on InAs(111)-Co surfaces2005In: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 574, no 2-3, p. 181-192Article in journal (Refereed)
    Abstract [en]

    We report a study of the initial interface formation of Co on InAs(1 1 1)A and B surfaces using high resolution photoelectron spectroscopy and scanning tunneling microscopy. We observe a strong chemical interaction between Co and, in particular, surface indium forming a metallic overlayer already below monolayer coverage. On annealed surfaces this overlayer agglomerates into islands, with a narrow size distribution. Furthermore, no two-dimensional electron gas is formed on InAs(1 1 1)A-Co in contrast to the clean surface.

  • 17. Shi, M.
    et al.
    Bendounan, A.
    Razzoli, E.
    Rosenkranz, S.
    Norman, M. R.
    Campuzano, J. C.
    Chang, J.
    Månsson, Martin
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Sassa, Y.
    Claesson, Tomas
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Patthey, L.
    Momono, N.
    Oda, M.
    Ido, M.
    Guerrero, S.
    Mudry, C.
    Mesot, J.
    Spectroscopic evidence for preformed Cooper pairs in the pseudogap phase of cuprates2009In: Europhysics letters, ISSN 0295-5075, E-ISSN 1286-4854, Vol. 88, no 2Article in journal (Refereed)
    Abstract [en]

    Angle-resolved photoemission on underdoped La1.895Sr0.105CuO4 reveals that in the pseudogap phase, the dispersion has two branches located above and below the Fermi level with a minimum at the Fermi momentum. This is characteristic of the Bogoliubov dispersion in the superconducting state. We also observe that the superconducting and pseudogaps have the same d-wave form with the same amplitude. Our observations provide direct evidence for preformed Cooper pairs, implying that the pseudogap phase is a precursor to superconductivity.

  • 18.
    Shi, Ming
    et al.
    Swiss Light Source, Paul Scherrer Institute, Villigen.
    Chang, Johan
    Laboratory for Neutron Scattering, ETH Zurich and Paul Scherrer Institute, Villigen .
    Pailhés, Stephane
    Laboratory for Neutron Scattering, ETH Zurich and Paul Scherrer Institute, Villigen .
    Norman, M. R.
    Materials Science Division, Argonne National Laboratory, Argonne.
    Campuzano, J. C.
    Materials Science Division, Argonne National Laboratory, Argonne.
    Månsson, Martin
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Bendounan, Azzedin
    Laboratory for Neutron Scattering, ETH Zurich and Paul Scherrer Institute, Villigen .
    Patthey, Luc
    Swiss Light Source, Paul Scherrer Institute, Villigen.
    Momono, Naoki
    Department of Physics, Hokkaido University, Sapporo.
    Oda, Migaku
    Department of Physics, Hokkaido University, Sapporo.
    Ido, Masayuki
    Department of Physics, Hokkaido University, Sapporo.
    Mudry, C.
    Condensed Matter Theory Group, Paul Scherrer Institute, Villigen.
    Mesot, Joël
    Laboratory for Neutron Scattering, ETH Zurich and Paul Scherrer Institute, Villigen .
    Coherent d-wave superconducting gap in underdoped La2-xSrxCuO4 by angle-resolved photoemission spectroscopy2008In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 101, no 4, p. 047002-Article in journal (Refereed)
    Abstract [en]

    We present angle-resolved photoemission spectroscopy data on moderately underdoped La1.855Sr0.145CuO4 at temperatures below and above the superconducting transition temperature. Unlike previous studies of this material, we observe sharp spectral peaks along the entire underlying Fermi surface in the superconducting state. These peaks trace out an energy gap that follows a simple d-wave form, with a maximum superconducting gap of 14 meV. Our results are consistent with a single gap picture for the cuprates. Furthermore our data on the even more underdoped sample La1.895Sr0.105CuO4 also show sharp spectral peaks, even at the antinode, with a maximum superconducting gap of 26 meV.

  • 19.
    Önsten, Anneli
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Månsson, Martin
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Muro, Takayuki
    Japan Synchrotron Radiation Research Institute (JASRI).
    Matsushita, Tomohiro
    Japan Synchrotron Radiation Research Institute (JASRI).
    Nakamura, Tetsuya
    Japan Synchrotron Radiation Research Institute (JASRI).
    Kinoshita, Toyohiko
    Japan Synchrotron Radiation Research Institute (JASRI).
    Karlsson, Ulf O.
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Tjernberg, Oscar
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Probing the valence band structure of Cu2O using high-energy angle-resolved photoelectron spectroscopy2007In: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, Vol. 76, no 11, p. 115127-1-115127-7Article in journal (Refereed)
    Abstract [en]

    We present angle-resolved photoemission data along the M-Gamma-M direction from a Cu2O(111) single crystal, collected at high photon energies (h nu=619 and 891 eV) and T=100 K. Because of the high photon energies and effective background subtraction, our data give a clear picture of the bulk band structure. The results confirm the existence of a hybridized Cu 3d-Cu 4s state located between the two main Cu 3d and O 2p band regions. Several theoretical studies have predicted the existence of this band, but until now it has not been detected in any photoemission measurements. The experimentally derived band structure is compared to local density approximation calculations with and without the Hubbard potential U. The clear band dispersion in our experimental data has enabled us to extract a refined Hubbard U value, which makes it possible to achieve a better agreement between theoretically calculated bands and experimental data.

  • 20.
    Önsten, Anneli
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Stoltz, Dunja
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Palmgren, Pål
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Yu, Shun
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Göthelid, Mats
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Karlsson, Ulf O.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    SO2 interaction with Zn(0001) and ZnO(0001) and the influence of water2013In: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 608, p. 31-43Article in journal (Refereed)
    Abstract [en]

    Photoelectron spectroscopy has been used to study room temperature adsorption of sulfur dioxide on clean and water exposed (0001) surfaces of zinc and zinc oxide. Water has no significant effect either on clean or on SO2 exposed Zn(0001) at the low water pressures used (p < 10(-7) mbar). In the Case of the zinc-terminated ZnO(0001) surface, however, water adsorbs dissociatively and OH groups are shown to have a considerable effect on SO2 surface reactions. A strong oxidation reaction occurs between Zn(0001) and SO2 giving various sulfur containing species. On ZnO(0001), SO2 interacts mainly with oxygen sites giving SO3 or SO4 species. It is shown that the ZnO(0001) sample preparation procedure can have large effects on surface chemical and physical properties. Samples cleaned by four different preparation procedures are investigated, namely sputtering only and sputtering followed by annealing at 450 degrees C, 530 degrees C and 600-650 degrees C. Annealing at 600 degrees C leads to a transition from a partly OH-terminated surface to a triangularly structured surface free from OH groups. Adsorption of SO2 on the latter surface leads to a decreased surface conductivity, which hampers photoemission measurements. Water is shown to block SO2 adsorption sites on both 450 degrees C and 530 degrees C annealed samples. On the latter sample. SO2 reduction has been observed to a small extent on the clean surface and to a larger extent when the surface is prehydroxylated. Here, we speculate that water, similar to hydrogen, generates surface zinc clusters on ZnO(0001). Zinc clusters could enable charge transfer to the antibonding LUMO of the SO2 molecule and subsequent dissociation.

  • 21.
    Önsten, Anneli
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Material Physics, MF.
    Stoltz, Dunja
    KTH, School of Information and Communication Technology (ICT), Material Physics, Material Physics, MF.
    Palmgren, Pål
    KTH, School of Information and Communication Technology (ICT), Material Physics, Material Physics, MF.
    Yu, Shun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Material Physics, MF.
    Claesson, Thomas
    KTH, School of Information and Communication Technology (ICT), Material Physics, Material Physics, MF.
    Göthelid, Mats
    KTH, School of Information and Communication Technology (ICT), Material Physics, Material Physics, MF.
    Karlsson, Ulf O.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Material Physics, MF.
    SO2 Interaction with Zn(0001) and ZnO(0001) and the Influenceof WaterManuscript (preprint) (Other academic)
1 - 21 of 21
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf