Resonant x-ray diffraction measurements in charge ordered kagome superconductors KV 3 Sb 5 and RbV 3 Sb 5 .

Autor: Scagnoli V; Laboratory for Mesoscopic Systems, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland.; Paul Scherrer Institute, 5232 Villigen PSI, Switzerland., Riddiford LJ; Laboratory for Mesoscopic Systems, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland.; Paul Scherrer Institute, 5232 Villigen PSI, Switzerland., Huang SW; Paul Scherrer Institute, 5232 Villigen PSI, Switzerland., Shi YG; Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China., Tu Z; Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing 100872, People's Republic of China.; Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing 100872, People's Republic of China., Lei H; Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing 100872, People's Republic of China.; Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing 100872, People's Republic of China., Bombardi A; Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom., Nisbet G; Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom., Guguchia Z; Paul Scherrer Institute, 5232 Villigen PSI, Switzerland.
Jazyk: angličtina
Zdroj: Journal of physics. Condensed matter : an Institute of Physics journal [J Phys Condens Matter] 2024 Feb 07; Vol. 36 (18). Date of Electronic Publication: 2024 Feb 07.
DOI: 10.1088/1361-648X/ad20a2
Abstrakt: We report on (resonant) x-ray diffraction experiments on the normal state properties of kagome-lattice superconductors KV 3 Sb 5 and RbV 3 Sb 5 . We have confirmed previous reports indicating that the charge density wave (CDW) phase is characterized by a doubling of the unit cell in all three crystallographic directions. By monitoring the temperature dependence of Bragg peaks associated with the CDW phase, we ascertained that it develops gradually over several degrees, as opposed to CsV 3 Sb 5 , where the CDW peak intensity saturates promptly just below the CDW transition temperature. Analysis of symmetry modes indicates that this behavior arises due to lattice distortions linked to the formation of CDWs. These distortions occur abruptly in CsV 3 Sb 5 , while they progress more gradually in RbV 3 Sb 5 and KV 3 Sb 5 . In contrast, the amplitude of the mode leading to the crystallographic symmetry breaking fromP6/mmmto Fmmm appears to develop more gradually in CsV 3 Sb 5 as well. Diffraction measurements close to the V K edge and the Sb L 1 edge show no sensitivity to inversion- or time-symmetry breaking, which are claimed to be associated with the onset of the CDW phase. The azimuthal angle dependence of the resonant diffraction intensity observed at the Sb L 1 edge is associated with the difference in the population of unoccupied states and the anisotropy of the electron density of certain Sb ions.
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Databáze: MEDLINE
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