Polaronic Quasiparticles in the Valence-Transition Compound <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>TmSe</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>−</mml:mo>
Exotic quasiparticle states have been proposed in mixed-valent compounds exhibiting valence transitions. However, clear spectroscopic evidence identifying these states has remained elusive. Using synchrotron-based hard x-ray and extreme ultraviolet photoemission spectroscopy, we have probed the Tm 3d and 4f emissions in TmSe_{1-x}Te_{x}, where a Te concentration-dependent semimetal-insulator transition occurs alongside the valence transition. Our photoemission results, which are characteristic of the bulk, track this combined transition across the critical concentration (x_{c}=0.29). Notably, our results reveal a noninteger valence for the insulating phase and a novel quasiparticle excitation in the semimetallic phase: a Holstein polaron that extends beyond the standard periodic Anderson model.
Authors
- M. Heber
- L. Dudy (ORCID: https://orcid.org/0000-0002-4204-5405)
- W. J. Choi (ORCID: https://orcid.org/0000-0003-1177-379X)
- Kai Roßnagel (ORCID: https://orcid.org/0000-0001-5107-0090)
- V. Hinkov (ORCID: https://orcid.org/0000-0002-6602-1002)
- Christoph Schlueter (ORCID: https://orcid.org/0000-0002-8745-3074)
- H.-D. Kim
- Hendrik Bentmann (ORCID: https://orcid.org/0000-0001-6317-5527)
- V. B. Zabolotnyy (ORCID: https://orcid.org/0000-0002-7632-7312)
- Stefan Müller (ORCID: https://orcid.org/0000-0002-4002-5005)
- Yong Seung Kwon (ORCID: https://orcid.org/0000-0001-6015-1183)
- Markus Scholz (ORCID: https://orcid.org/0000-0001-5669-9912)
- Jonathan D. Denlinger (ORCID: https://orcid.org/0000-0001-7645-1631)
- Chang‐Jong Kang (ORCID: https://orcid.org/0000-0003-2895-4888)
- Chul-Hee Min (ORCID: https://orcid.org/0000-0002-2732-8773)
- E. D. L. Rienks (ORCID: https://orcid.org/0000-0002-9192-0552)
- M. Kalläne
- Andrei Gloskovskii (ORCID: https://orcid.org/0000-0002-2291-5207)
- Nils Wind (ORCID: https://orcid.org/0000-0002-7758-0678)
- F. Reinert (ORCID: https://orcid.org/0000-0001-7993-1171)
- Tien‐Lin Lee (ORCID: https://orcid.org/0000-0001-6935-5983)
Institutions
- Pohang University of Science and Technology (KR)
- Lawrence Berkeley National Laboratory (US)
- Universität Hamburg (DE)
- Daegu Gyeongbuk Institute of Science and Technology (KR)
- Chungnam National University (KR)
- Norwegian University of Science and Technology (NO)
- University of Würzburg (DE)
- Helmholtz-Zentrum Berlin für Materialien und Energie (DE)
- Synchrotron soleil (FR)
- Deutsches Elektronen-Synchrotron DESY (DE)
- Diamond Light Source (GB)
- Christian-Albrechts-Universität zu Kiel (DE)
- Institut für Technische und Angewandte Physik (Germany) (DE)
- Pohang Accelerator Laboratory
- Advanced Light Source
Publication Details
- Journal
- Physical Review Letters
- Published
- 2025-09-24
- DOI
- https://doi.org/10.1103/72dv-ynm2
- Primary Topic
- Topological Materials and Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00