Change search
Refine search result
1 - 12 of 12
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.
    Borysov, Stanislav S.
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Geilhufe, R. Matthias
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Balatsky, Alexander V.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Organic materials database: An open-access online database for data mining2017In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, no 2, article id e0171501Article in journal (Refereed)
    Abstract [en]

    We present an organic materials database (OMDB) hosting thousands of Kohn-Sham electronic band structures, which is freely accessible online at http://omdb.diracmaterials.org. The OMDB focus lies on electronic structure, density of states and other properties for purely organic and organometallic compounds that are known to date. The electronic band structures are calculated using density functional theory for the crystal structures contained in the Crystallography Open Database. The OMDB web interface allows users to retrieve materials with specified target properties using non-trivial queries about their electronic structure. We illustrate the use of the OMDB and how it can become an organic part of search and prediction of novel functional materials via data mining techniques. As a specific example, we provide data mining results for metals and semiconductors, which are known to be rare in the class of organic materials.

  • 2.
    Borysov, Stanislav S.
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Olsthoorn, Bart
    Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden.;Stockholm Univ, Dept Phys, SE-10691 Stockholm, Sweden..
    Gedik, M. Berk
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Geilhufe, R. Matthias
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Balatsky, Alexander V.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA..
    Online search tool for graphical patterns in electronic band structures2018In: NPJ COMPUTATIONAL MATERIALS, ISSN 2057-3960, Vol. 4, article id UNSP 46Article in journal (Refereed)
    Abstract [en]

    Many functional materials can be characterized by a specific pattern in their electronic band structure, for example, Dirac materials, characterized by a linear crossing of bands; topological insulators, characterized by a "Mexican hat" pattern or an effectively free electron gas, characterized by a parabolic dispersion. To find material realizations of these features, manual inspection of electronic band structures represents a relatively easy task for a small number of materials. However, the growing amount of data contained within modern electronic band structure databases makes this approach impracticable. To address this problem, we present an automatic graphical pattern search tool implemented for the electronic band structures contained within the Organic Materials Database. The tool is capable of finding user-specified graphical patterns in the collection of thousands of band structures from high-throughput calculations in the online regime. Using this tool, it only takes a few seconds to find an arbitrary graphical pattern within the ten electronic bands near the Fermi level for 26,739 organic crystals. The source code of the developed tool is freely available and can be adapted to any other electronic band structure database.

  • 3. Commeau, Benjamin
    et al.
    Geilhufe, R. Matthias
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm University, Sweden.
    Fernando, Gayanath W.
    Balatsky, Alexander V.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm University, Sweden.
    Structural and electronic properties of alpha-(BEDT-TTF)(2)I-3, ss-(BEDT-TTF)(2)I-3, and kappa-(BEDT-TTF)(2)X-3 (X = I, F, Br, Cl) organic charge transfer salts2017In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 96, no 12, article id 125135Article in journal (Refereed)
    Abstract [en]

    (BEDT-TFF)(2)I-3 charge transfer salts are reported to show superconductivity and pressure-induced quasi-twodimensional Dirac cones at the Fermi level. By performing state of the art ab initio calculations in the framework of density functional theory, we investigate the structural and electronic properties of the three structural phases alpha, beta, and kappa(.) We furthermore report about the irreducible representations of the corresponding electronic band structures, symmetry of their crystal structure, and the origin of band crossings. Additionally, we discuss the chemically induced strain in kappa-(BEDT-TTF)(2)I-3 achieved by replacing the iodine layer with other halogens: fluorine, bromine, and chlorine. In the case of kappa-(BEDT-TTF)(2)F-3, we identify topologically protected crossings within the band structure. These crossings are forced to occur due to the nonsymmorphic nature of the crystal. The calculated electronic structures presented here are added to the organic materials database (OMDB).

  • 4.
    Geilhufe, Matthias
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Balatsky, Alexander V.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Institute for Materials Science, Los Alamos National Laboratory, Los Alamos, USA; Department of Physics, University of Connecticut, USA.
    Symmetry analysis of odd- and even-frequency superconducting gap symmetries for time-reversal symmetric interactions2018In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 97, no 2, article id 024507Article in journal (Refereed)
    Abstract [en]

    Odd-frequency superconductivity describes a class of superconducting states where the superconducting gap is an odd function in relative time and Matsubara frequency. We present a group theoretical analysis based on the linearized gap equation in terms of Shubnikov groups of the second kind. By discussing systems with spin-orbit coupling and an interaction kernel which is symmetric under the reversal of relative time, we show that both even-and odd-frequency gaps are allowed to occur. Specific examples are discussed for the square lattice, the octahedral lattice, and the tetragonal lattice. For irreducible representations that are even under the reversal of relative time the common combinations of s- and d-wave spin singlet and p-wave spin triplet gaps are revealed, irreducible representations that are odd under reversal of relative time give rise to s- and d-wave spin triplet and p-wave spin singlet gaps. Furthermore, we discuss the construction of a generalized Ginzburg-Landau theory in terms of the associated irreducible representations. The result complements the established classification of superconducting states of matter.

  • 5.
    Geilhufe, Matthias
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Borysov, Stanislav
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Bouhon, A.
    Balatsky, Alexander V.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Data Mining for Three-Dimensional Organic Dirac Materials: Focus on Space Group2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, no 1, article id 7298Article in journal (Refereed)
    Abstract [en]

    We combined the group theory and data mining approach within the Organic Materials Database that leads to the prediction of stable Dirac-point nodes within the electronic band structure of three-dimensional organic crystals. We find a particular space group P212121 (#19) that is conducive to the Dirac nodes formation. We prove that nodes are a consequence of the orthorhombic crystal structure. Within the electronic band structure, two different kinds of nodes can be distinguished: 8-fold degenerate Dirac nodes protected by the crystalline symmetry and 4-fold degenerate Dirac nodes protected by band topology. Mining the Organic Materials Database, we present band structure calculations and symmetry analysis for 6 previously synthesized organic materials. In all these materials, the Dirac nodes are well separated within the energy and located near the Fermi surface, which opens up a possibility for their direct experimental observation.

  • 6.
    Geilhufe, Matthias
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden.
    Commeau, Benjamin
    Univ Connecticut, 2152 Hillside Rd,U-3046, Storrs, CT 06269 USA..
    Fernando, Gayanath W.
    Univ Connecticut, 2152 Hillside Rd,U-3046, Storrs, CT 06269 USA..
    Chemical-Strain Induced Tilted Dirac Nodes in (BEDT-TTF)(2)X-3 (X = I, Cl, Br, F) Based Charge-Transfer Salts2018In: Physica Status Solidi. Rapid Research Letters, ISSN 1862-6254, E-ISSN 1862-6270, Vol. 12, no 11, article id 1800081Article in journal (Refereed)
    Abstract [en]

    The identification of novel multifunctional Dirac materials has been an ongoing effort. In this connection quasi 2-dimensional (BEDT-TTF)-based charge transfer salts are widely discussed. Here, we report about the electronic structure of alpha-(BEDT-TTF)(2)I-3 and kappa-(BEDT-TTF)(2)I-3 under a hypothetical substitution of iodine with the halogens bromine, chlorine, and fluorine. The decreasing size of the anion layer corresponds to applying chemical strain which increases tremendously in the case of (BEDT-TTF)(2)F-3. We perform structural optimization and electronic structure calculations in the framework of density functional theory, incorporating, first, the recently developed strongly constrained and appropriately normed semilocal density functional SCAN, and, second, van der Waals corrections to the PBE exchange correlation functional by means of the dDsC dispersion correction method. In the case of alpha-(BEDT-TTF)(2)F-3, the formation of over-tilted Dirac-type-II nodes within the quasi two-dimensional Brillouin zone can be found. For kappa-(BEDT-TTF)(2)F-3, the recently reported topological transition within the electronic band structure cannot be revealed.

  • 7.
    Geilhufe, Matthias
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm Univ, Roslagstullsbacken 23, S-10691 Stockholm, Sweden.
    Guinea, Francisco
    Imdea Nanosci, Faraday 9, Madrid 28015, Spain.;Univ Manchester, Sch Phys & Astron, Manchester M13 9PY, Lancs, England..
    Juricic, Vladimir
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm Univ, Roslagstullsbacken 23, S-10691 Stockholm, Sweden.
    Hund nodal line semimetals: The case of a twisted magnetic phase in the double-exchange model2019In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 99, no 2, article id 020404Article in journal (Refereed)
    Abstract [en]

    We propose a class of topological metals, which we dub Hund nodal line semimetals, arising from the strong Coulomb interaction encoded in the Hund's coupling between itinerant electrons and localized spins. We here consider a particular twisted spin configuration, which is realized in the double-exchange model which describes the manganite oxides. The resulting effective tetragonal lattice of electrons with hoppings tied to the local spin features an antiunitary nonsymmorphic symmetry that, in turn, together with another nonsymmorphic but unitary glide-mirror symmetry, protects crossings of a double pair of bands along a high-symmetry line on the Brillouin zone boundary. We also discuss the stability of Hund nodal line semimetals with respect to symmetry breaking arising from various perturbations of the twisted phase. Our results motivate further studies of other realizations of this state of matter, for instance, in different spin backgrounds, properties of its drumhead surface states, as well as its stability to disorder and interactions among the itinerant electrons.

  • 8.
    Geilhufe, Matthias
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm Univ.
    Hergert, Wolfram
    Martin Luther Univ Halle Wittenberg, Inst Phys, Halle, Germany..
    GTPack: A Mathematica Group Theory Package for Application in Solid-State Physics and Photonics2018In: Frontiers in Physics, E-ISSN 2296-424X, Vol. 6, article id 86Article in journal (Refereed)
    Abstract [en]

    We present the Mathematica group theory package GTPack providing about 200 additional modules to the standard Mathematica language. The content ranges from basic group theory and representation theory to more applied methods like crystal field theory, tight-binding and plane-wave approaches capable for symmetry based studies in the fields of solid-state physics and photonics. GTPack is freely available via http://GTPack.org. The package is designed to be easily accessible by providing a complete Mathematica-style documentation, an optional input validation and an error strategy. We illustrate the basic framework of the package and show basic examples to present the functionality. Furthermore, we give a complete list of the implemented commands including references for algorithms within the Supplementary Material.

  • 9.
    Geilhufe, Matthias
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden..
    Olsthoorn, Bart
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden..
    Ferella, Alfredo D.
    Fysikum Stockholm Univ, Oskar Klein Ctr Cosmoparticle Phys, Roslagstullsbacken 21, SE-10961 Stockholm, Sweden..
    Koski, Timo
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Mathematical Statistics.
    Kahlhoefer, Felix
    Rhein Westfal TH Aachen, Inst Theoret Particle Phys & Cosmol TTK, D-52056 Aachen, Germany..
    Conrad, Jan
    Fysikum Stockholm Univ, Oskar Klein Ctr Cosmoparticle Phys, Roslagstullsbacken 21, SE-10961 Stockholm, Sweden..
    Balatsky, Alexander V.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden.;Univ Connecticut, 2152 Hillside Rd,U-3046, Storrs, CT 06269 USA.;Los Alamos Natl Lab, Inst Mat Sci, Los Alamos, NM 87545 USA..
    Materials Informatics for Dark Matter Detection2018In: Physica Status Solidi. Rapid Research Letters, ISSN 1862-6254, E-ISSN 1862-6270, Vol. 12, no 11, article id 1800293Article in journal (Refereed)
    Abstract [en]

    Dark Matter particles are commonly assumed to be weakly interacting massive particles (WIMPs) with a mass in the GeV to TeV range. However, recent interest has shifted toward lighter WIMPs, which are more difficult to probe experimentally. A detection of sub-GeV WIMPs will require the use of small gap materials in sensors. Using recent estimates of the WIMP mass, we identify the relevant target space toward small gap materials (100 to 10 meV). Dirac Materials, a class of small- or zero-gap materials, emerge as natural candidates for sensors for Dark Matter detection. We propose the use of informatics tools to rapidly assay materials band structures to search for small gap semiconductors and semimetals, rather than focusing on a few preselected compounds. As a specific example of the proposed strategy, we use the organic materials database () to identify organic candidates for sensors: the narrow band gap semiconductors BNQ-TTF and DEBTTT with gaps of 40 and 38 meV, and the Dirac-line semimetal (BEDT-TTF)center dot Br which exhibits a tiny gap of approximate to 50 meV when spin-orbit coupling is included. We outline a novel and powerful approach to search for dark matter detection sensor materials by means of a rapid assay of materials using informatics tools.

  • 10.
    Geilhufe, R. Matthias
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Bouhon, Adrien
    Borysov, Stanislav S.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Balatsky, Alexander V.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Three-dimensional organic Dirac-line materials due to nonsymmorphic symmetry: A data mining approach2017In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 95, no 4, article id 041103Article in journal (Refereed)
    Abstract [en]

    A datamining study of electronic Kohn-Sham band structures was performed to identify Dirac materials within the Organic Materials Database. Out of that, the three-dimensional organic crystal 5,6-bis(trifluoromethyl)-2-methoxy-1H-1,3-diazepine was found to host different Dirac-line nodes within the band structure. From a group theoretical analysis, it is possible to distinguish between Dirac-line nodes occurring due to twofold degenerate energy levels protected by the monoclinic crystalline symmetry and twofold degenerate accidental crossings protected by the topology of the electronic band structure. The obtained results can be generalized to all materials having the space group P2(1)/c (No. 14, C-2h(5)) by introducing three distinct topological classes.

  • 11. Polyakov, A.
    et al.
    Tusche, C.
    Ellguth, M.
    Crozier, E. D.
    Mohseni, K.
    Otrokov, M. M.
    Zubizarreta, X.
    Vergniory, M. G.
    Geilhufe, Matthias
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Max-Planck-Institut für Mikrostrukturphysik, Germany.
    Chulkov, E. V.
    Ernst, A.
    Meyerheim, H. L.
    Parkin, S. S. P.
    Instability of the topological surface state in Bi2Se3 upon deposition of gold2017In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 95, no 18, article id 180202Article in journal (Refereed)
    Abstract [en]

    Momentum-resolved photoemission spectroscopy indicates the instability of the Dirac surface state upon deposition of gold on the (0001) surface of the topological insulator Bi2Se3. Based on the structure model derived from extended x-ray absorption fine structure experiments showing that gold atoms substitute bismuth atoms, first-principles calculations provide evidence that a gap appears due to hybridization of the surface state with gold d states near the Fermi level. Our findings provide insights into the mechanisms affecting the stability of the surface state.

  • 12.
    Polyakov, A.
    et al.
    Max Planck Inst Mikrostrukturphys, Weinberg 2, D-06120 Halle, Germany..
    Tusche, C.
    Max Planck Inst Mikrostrukturphys, Weinberg 2, D-06120 Halle, Germany.;Forschungszentrum Julich, Peter Grunberg Inst PGI 6, D-52425 Julich, Germany..
    Ellguth, M.
    Max Planck Inst Mikrostrukturphys, Weinberg 2, D-06120 Halle, Germany.;Johannes Gutenberg Univ Mainz, Inst Phys, Staudingerweg 7, D-55116 Mainz, Germany..
    Crozier, E. D.
    Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada..
    Mohseni, K.
    Max Planck Inst Mikrostrukturphys, Weinberg 2, D-06120 Halle, Germany..
    Otrokov, M. M.
    Univ Basque Country, CFM, Dept Fis Mat, MPC, San Sebastian 20080, Basque Country, Spain.;Ctr Mixto CSIC UPV EHU, San Sebastian 20080, Basque Country, Spain.;Tomsk State Univ, Tomsk 634050, Russia.;St Petersburg State Univ, St Petersburg 198505, Russia..
    Zubizarreta, X.
    Max Planck Inst Mikrostrukturphys, Weinberg 2, D-06120 Halle, Germany..
    Vergniory, M. G.
    Max Planck Inst Mikrostrukturphys, Weinberg 2, D-06120 Halle, Germany.;DIPC, San Sebastian 20018, Basque Country, Spain..
    Geilhufe, Matthias
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Max Planck Inst Mikrostrukturphys, Weinberg 2, D-06120 Halle, Germany.;KTH Royal Inst Technol, Stockholm Ctr Quantum Mat, Nordita, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden.;Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden..
    Chulkov, E. V.
    Univ Basque Country, CFM, Dept Fis Mat, MPC, San Sebastian 20080, Basque Country, Spain.;Ctr Mixto CSIC UPV EHU, San Sebastian 20080, Basque Country, Spain.;Tomsk State Univ, Tomsk 634050, Russia.;DIPC, San Sebastian 20018, Basque Country, Spain..
    Ernst, A.
    Max Planck Inst Mikrostrukturphys, Weinberg 2, D-06120 Halle, Germany.;Johannes Kepler Univ Linz, Inst Theoret Phys, A-4040 Linz, Austria..
    Meyerheim, H. L.
    Max Planck Inst Mikrostrukturphys, Weinberg 2, D-06120 Halle, Germany..
    Parkin, S. S. P.
    Max Planck Inst Mikrostrukturphys, Weinberg 2, D-06120 Halle, Germany..
    Reply to "Comment on 'Instability of the topological surface state in Bi2Se3 upon deposition of gold'"2018In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 98, no 13, article id 136202Article in journal (Refereed)
    Abstract [en]

    In the Comment on our publication [Phys. Rev. B 95, 180202(R) (2017)], R. A. Gordon claims that our main conclusion is not valid, namely that gold atoms deposited in situ on the (0001) surface of single-crystalline Bi2Se3 reside in substitutional sites, i.e., replacing bismuth atoms within the topmost quintuple layer (QL). Based on x-ray absorption near-edge (XANES) spectra and a re-evaluation of extended x-ray absorption fine structure (EXAFS) data above the Au L-III edge, R. A. Gordon concludes that Au resides in a twofold environment as a result of an interface reaction leading to an Au2S-type local structure, in which gold adopts an Au(I) state and is linearly coordinated by selenium atoms. In this Reply, we will confirm the results published in the original paper and their interpretation that Au atoms reside in the substitutional site.

1 - 12 of 12
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