Journal Article

FZJ-2024-05332

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Evidence for distortion-induced local electric polarization in α-RuCl3

Mi, X. ; Hou, D. ; Wang, X.FZJ* ; Hammouda, S.FZJ* ; Liu, C. ; Xiong, Z. ; Li, H. ; Liu, Y. ; Wang, G. ; Wang, A. ; Chai, Y. ; Qi, Y. ; Li, W. ; Zhou, X. ; Su, Y.FZJ* ; Khomskii, D. I. ; He, M. (Corresponding author) ; Sheng, Z. (Corresponding author) ; Sun, Y. (Corresponding author)

2024
Springer Heidelberg

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Please use a persistent id in citations: doi:10.1007/s11433-024-2417-8

Abstract: The spin-orbit assisted Mott insulator α-RuCl3 is a prime candidate for material realization of the Kitaev quantum spin liquid. While little attention has been paid to charge degrees of freedom, charge effects, such as electric polarization, may arise in this system. Here, we report distortion-induced local electric polarization in α-RuCl3 as evidenced by single-crystal X-ray diffraction, second harmonic generation (SHG) and dielectric measurements. The SHG signal appears at room temperature and develops substantially in the Kitaev paramagnetic state when short-range spin correlations come into play. Despite sizable pyroelectric currents in the Kitaev paramagnetic state, the absence of hysteresis in the polarization-electric field (P-E) points to the short-range nature of electric polarization. This localized electric polarization is likely the result of distortion-induced charge dimerization, achieved through virtual hopping-induced charge redistribution. In addition, the electric polarization is boosted by short-range spin correlations via spin-phonon coupling in the Kitaev paramagnetic state. Our results emphasize the importance of charge degrees of freedom in α-RuCl3, which establish a novel platform to investigate charge effects in Kitaev materials.

Keyword(s): Information and Communication (1st) ; Magnetism (2nd) ; Condensed Matter Physics (2nd)

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Contributing Institute(s):

1. JCNS-FRM-II (JCNS-FRM-II)
2. Heinz Maier-Leibnitz Zentrum (MLZ)
3. JCNS-4 (JCNS-4)

Research Program(s):

1. 6G4 - Jülich Centre for Neutron Research (JCNS) (FZJ) (POF4-6G4) (POF4-6G4)
2. 632 - Materials – Quantum, Complex and Functional Materials (POF4-632) (POF4-632)

Experiment(s):

1. Measurement at external facility

Appears in the scientific report 2024

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Database coverage:
; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; DEAL Springer ; DEAL Springer ; Essential Science Indicators ; IF >= 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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