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首页|Optical Excitations of Flat Bands Induced by Exciton Condensation in Ta$_2$Pd$_3$Te$_{5}$

Optical Excitations of Flat Bands Induced by Exciton Condensation in Ta$_2$Pd$_3$Te$_{5}$

Optical Excitations of Flat Bands Induced by Exciton Condensation in Ta$_2$Pd$_3$Te$_{5}$

来源:Arxiv_logoArxiv
英文摘要

We report on the charge dynamics of Ta$_2$Pd$_3$Te$_5$ using temperature-dependent optical spectroscopy with polarized light. We observe a metal-insulator transition characterized by the collapse of Drude response and the emergence of sharp and narrow absorption peaks at low temperatures. Unlike previous excitonic insulator candidates such as TiSe$_2$ and Ta$_2$NiSe$_5$, where the excitonic order is intertwined with charge density wave or structural instabilities, the sharp features in Ta$_2$Pd$_3$Te$_5$ point to intrinsic excitonic excitations associated with ultra-flat bands driven by many-body renormalization of the band structure via spontaneous exciton condensation. Our findings thus provide clear-cut optical evidence for exciton condensation in a bulk crystal and establish Ta$_2$Pd$_3$Te$_5$ as a promising platform for exploring correlated quantum phases and novel excitonic phenomena.

Shaohui Yi、Zhiyu Liao、Chenhao Liang、Sheng Zhang、Xiutong Deng、Yongjie Xie、Lincong Zheng、Yujie Wang、Yubiao Wu、Zhijun Wang、Youguo Shi、Xianggang Qiu、Bing Xu

物理学

Shaohui Yi,Zhiyu Liao,Chenhao Liang,Sheng Zhang,Xiutong Deng,Yongjie Xie,Lincong Zheng,Yujie Wang,Yubiao Wu,Zhijun Wang,Youguo Shi,Xianggang Qiu,Bing Xu.Optical Excitations of Flat Bands Induced by Exciton Condensation in Ta$_2$Pd$_3$Te$_{5}$[EB/OL].(2025-06-23)[2025-07-18].https://arxiv.org/abs/2506.18350.点此复制

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