Fluctuated lattice-driven charge density wave far above the condensation temperature in kagome superconductor KV$_3$Sb$_5$

Fuente: arXiv
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Main Authors: Liu, Haoran, Duan, Shaofeng, Liu, Xiangqi, Liu, Zhihua, Wang, Shichong, Gu, Lingxiao, Huang, Jiongyu, Yang, Wenxuan, Liu, Jianzhe, Qian, Dong, Guo, Yanfeng, Zhang, Wentao
Format: Preprint
Published: 2025
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author Liu, Haoran
Duan, Shaofeng
Liu, Xiangqi
Liu, Zhihua
Wang, Shichong
Gu, Lingxiao
Huang, Jiongyu
Yang, Wenxuan
Liu, Jianzhe
Qian, Dong
Guo, Yanfeng
Zhang, Wentao
author_facet Liu, Haoran
Duan, Shaofeng
Liu, Xiangqi
Liu, Zhihua
Wang, Shichong
Gu, Lingxiao
Huang, Jiongyu
Yang, Wenxuan
Liu, Jianzhe
Qian, Dong
Guo, Yanfeng
Zhang, Wentao
contents The kagome material AV$_3$Sb$_5$ exhibits multiple exotic orders, including an unconventional charge density wave (CDW). Elucidating the underlying mechanism behind the CDW transition is crucial for unraveling the complex interactions among these phases. However, the driving force of the CDW remains a topic of debate due to the intertwined interactions among the system's various excitations. Here we investigated the CDW transition in KV$_3$Sb$_5$ by isolating the ultrafast electronic phase transition using time- and angleresolved photoemission spectroscopy. An ultrafast electronic phase transition was observed at a critical photoexcitation fluence, F$_c$, without reduction in CDW lattice-distortion-induced band folding. This folded band persisted up to 150 K under equilibrium heating, well above the CDW condensation temperature of T$_c$ = 78 K. Notably, the pump-induced band shifts at F$_c$ were comparable to those caused by thermal effects at T$_c$. These findings suggest that in KV$_3$Sb$_5$, a fluctuating lattice-driven in-plane CDW emerges above 150 K, with out-of-plane electronic correlations leading to the $2\times2 \times 2$ CDW near T$_c$, offering key insights into the interplay between the electronic and structural dynamics in AV$_3$Sb$_5$.
format Preprint
id arxiv_https___arxiv_org_abs_2504_16620
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Fluctuated lattice-driven charge density wave far above the condensation temperature in kagome superconductor KV$_3$Sb$_5$
Liu, Haoran
Duan, Shaofeng
Liu, Xiangqi
Liu, Zhihua
Wang, Shichong
Gu, Lingxiao
Huang, Jiongyu
Yang, Wenxuan
Liu, Jianzhe
Qian, Dong
Guo, Yanfeng
Zhang, Wentao
Strongly Correlated Electrons
Materials Science
Superconductivity
The kagome material AV$_3$Sb$_5$ exhibits multiple exotic orders, including an unconventional charge density wave (CDW). Elucidating the underlying mechanism behind the CDW transition is crucial for unraveling the complex interactions among these phases. However, the driving force of the CDW remains a topic of debate due to the intertwined interactions among the system's various excitations. Here we investigated the CDW transition in KV$_3$Sb$_5$ by isolating the ultrafast electronic phase transition using time- and angleresolved photoemission spectroscopy. An ultrafast electronic phase transition was observed at a critical photoexcitation fluence, F$_c$, without reduction in CDW lattice-distortion-induced band folding. This folded band persisted up to 150 K under equilibrium heating, well above the CDW condensation temperature of T$_c$ = 78 K. Notably, the pump-induced band shifts at F$_c$ were comparable to those caused by thermal effects at T$_c$. These findings suggest that in KV$_3$Sb$_5$, a fluctuating lattice-driven in-plane CDW emerges above 150 K, with out-of-plane electronic correlations leading to the $2\times2 \times 2$ CDW near T$_c$, offering key insights into the interplay between the electronic and structural dynamics in AV$_3$Sb$_5$.
title Fluctuated lattice-driven charge density wave far above the condensation temperature in kagome superconductor KV$_3$Sb$_5$
topic Strongly Correlated Electrons
Materials Science
Superconductivity
url https://arxiv.org/abs/2504.16620