Mapping the unoccupied state dispersions in ${\mathrm{Ta}}_{2}{\mathrm{NiSe}}_{5}$ with resonant inelastic x-ray scattering
- Monney, Claude Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700 Fribourg, Switzerland
- Herzog, Marc Institut für Physik und Astronomie, Universität Potsdam, 14476 Potsdam, Germany
- Pulkkinen, Aki Département de Physique and Fribourg Center for Nanomaterials, Université de Fribourg, 1700 Fribourg, Switzerland - School of Engineering Science, LUT University, 53850 Lappeenranta, Finland
- Huang, Y. Swiss Light Source, Photon Science Division, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland - Beijing National Lab for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, 100190 Beijing, China
- Pelliciari, Jonathan Swiss Light Source, Photon Science Division, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland - NSLS-II, Brookhaven National Laboratory, Upton, New York 11973, USA
- Olalde-Velasco, P. Swiss Light Source, Photon Science Division, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland - Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
- Katayama, Naoyuk Department of Applied Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
- Nohara, Minoru Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
- Takagi, Hide Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany - Department of Physics, University of Tokyo, 113-8654 Tokyo, Japan
- Schmitt, Thorsten Swiss Light Source, Photon Science Division, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
- Mizokawa, Takashi Department of Applied Physics, Waseda University, Shinjuku, 169-8555 Tokyo, Japan
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25.08.2020
Published in:
- Physical Review B. - 2020, vol. 102, no. 8, p. 085148
English
The transition metal chalcogenide Ta2NiSe5 undergoes a second-order phase transition at Tc=328K involving a small lattice distortion. Below Tc, a band gap at the center of its Brillouin zone increases up to about 0.35 eV. In this work, we study the electronic structure of Ta2NiSe5 in its low-temperature semiconducting phase, using resonant inelastic x-ray scattering (RIXS) at the Ni L3 edge. In addition to a weak fluorescence response, we observe a collection of intense Raman-like peaks that we attribute to electron-hole excitations. Using density functional theory calculations of its electronic band structure, we identify the main Raman-like peaks as interband transitions between valence and conduction bands. By performing angle-dependent RIXS measurements, we uncover the dispersion of these electron-hole excitations that allows us to extract the low-energy boundary of the electron-hole continuum. From the dispersion of the valence band measured by angle-resolved photoemission spectroscopy, we derive the effective mass of the lowest unoccupied conduction band.
- Faculty
- Faculté des sciences et de médecine
- Department
- Département de Physique
- Language
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- English
- Classification
- Physics
- License
- License undefined
- Identifiers
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- RERO DOC 329491
- DOI 10.1103/PhysRevB.102.085148
- Persistent URL
- https://folia.unifr.ch/unifr/documents/309012
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