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Main Authors: Liu, Hao-Tian, Huang, Junkang, Zhou, Tao, Huang, Wen
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2406.16398
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author Liu, Hao-Tian
Huang, Junkang
Zhou, Tao
Huang, Wen
author_facet Liu, Hao-Tian
Huang, Junkang
Zhou, Tao
Huang, Wen
contents The $A$V$_3$Sb$_5$ ($A=$ K, Rb, Cs) family of Kagome metals hosts unconventional charge density wave order whose nature is still an open puzzle. Accumulated evidences point to a time-reversal symmetry breaking orbital flux phase that carries loop currents. Such an order may support anomalous Hall effect. However, the polar Kerr effect measurements that probe the a.c. anomalous Hall conductivity seems to have yielded contradictory results. We first argue on symmetry grounds that some previously proposed orbital flux order, most notably the one with Star-of-David distortion, shall not give rise to anomalous Hall or polar Kerr effects. We further take the tri-hexagonal orbital flux phase as an exemplary Kagome flux order that does exhibit anomalous Hall response, and show that the Kerr rotation angle at two relevant experimental optical frequencies generally reaches microradians to sub-milliradians levels. A particularly sharp resonance enhancement is observed at around $\hbar ω=1$ eV, suggesting exceedingly large Kerr rotation at the corresponding probing frequencies not yet accessed by previous experiments. Our study can help to interpret the Kerr measurements on $A$V$_3$Sb$_5$ and to eventually resolve the nature of their CDW order.
format Preprint
id arxiv_https___arxiv_org_abs_2406_16398
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Constraints on the orbital flux phase in $A$V$_3$Sb$_5$ from polar Kerr effect
Liu, Hao-Tian
Huang, Junkang
Zhou, Tao
Huang, Wen
Mesoscale and Nanoscale Physics
Materials Science
Superconductivity
The $A$V$_3$Sb$_5$ ($A=$ K, Rb, Cs) family of Kagome metals hosts unconventional charge density wave order whose nature is still an open puzzle. Accumulated evidences point to a time-reversal symmetry breaking orbital flux phase that carries loop currents. Such an order may support anomalous Hall effect. However, the polar Kerr effect measurements that probe the a.c. anomalous Hall conductivity seems to have yielded contradictory results. We first argue on symmetry grounds that some previously proposed orbital flux order, most notably the one with Star-of-David distortion, shall not give rise to anomalous Hall or polar Kerr effects. We further take the tri-hexagonal orbital flux phase as an exemplary Kagome flux order that does exhibit anomalous Hall response, and show that the Kerr rotation angle at two relevant experimental optical frequencies generally reaches microradians to sub-milliradians levels. A particularly sharp resonance enhancement is observed at around $\hbar ω=1$ eV, suggesting exceedingly large Kerr rotation at the corresponding probing frequencies not yet accessed by previous experiments. Our study can help to interpret the Kerr measurements on $A$V$_3$Sb$_5$ and to eventually resolve the nature of their CDW order.
title Constraints on the orbital flux phase in $A$V$_3$Sb$_5$ from polar Kerr effect
topic Mesoscale and Nanoscale Physics
Materials Science
Superconductivity
url https://arxiv.org/abs/2406.16398