Ta₂Se₈I charge density wave

Litskevich, Maksim; Hossain, Md Shafayat; Zhang, Songbo; Zi-Jia, Cheng; Guin, Satya N.; Nitesh, Kumar; Chandra, Shekhar; Zhiwei, Wang; Li, Yongkai; Chang, Guoqing; Yin, Jiaxin; Zhang, Qi; Cheng, Guangming; Cochran, Tyler A.; Shumiya, Nana; Jiang, Yuxiao; Yang, Xian P.; Multer, Daniel; Liu, Xiaoxiong; Yao, N.; Yao, Yugui; Felser, Claudia; Neupert, Titus; Hasan, M. Zahid

Ta₂Se₈I charge density wave

Edge state stable to T_c

Scanning tunnelling microscopy reveals an in-gap boundary mode at monolayer step edges of Ta₂Se₈I, persisting up to the charge ordering temperature with modulations matching the CDW wavevector, challenging the existing axion insulator interpretation.

Litskevich, Maksim · Hossain, Md Shafayat · Zhang, Songbo · Zi-Jia, Cheng · Guin, Satya N. · Nitesh, Kumar · Chandra, Shekhar · Zhiwei, Wang · Li, Yongkai · Chang, Guoqing · Yin, Jiaxin · Zhang, Qi · Cheng, Guangming · Cochran, Tyler A. · Shumiya, Nana · Jiang, Yuxiao · Yang, Xian P. · Multer, Daniel · Liu, Xiaoxiong · Yao, N. · Yao, Yugui · Felser, Claudia · Neupert, Titus · Hasan, M. Zahid

Nature Physics 2024

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In-gap boundary mode persists up to charge ordering temperature

Modulations along edge match charge density wave wavevector

Monolayer step edge