Chirality manipulation of ultrafast phase switchings in a correlated CDW-Weyl semimetal
In: Nature Communications 15, 785 (2024); (2023)
Online
report
A recently emerging concept for quantum phase discovery is the controlled gapping of linear band crossings in topological semimetals. For example, achieving topological superconducting and charge-density-wave (CDW) gapping could introduce Majorana zero modes and axion electrodynamics, respectively. Light engineering of correlation gaps in topological materials provides a new avenue of achieving exotic topological phases inaccessible by conventional tuning methods such as doping and straining. Here we demonstrate a light control of correlation gaps and ultrafast phase switchings in a model CDW and polaron insulator (TaSe$_4$)$_2$I recently predicted to be an axion insulator. Our ultrafast terahertz photocurrent spectroscopy reveals a two-step, non-thermal melting of polarons and electronic CDW gap via studying the fluence dependence of a {\em longitudinal} circular photogalvanic current. The helicity-dependent photocurrent observed along the propagation of light reveals continuous ultrafast switchings from the polaronic state, to the CDW (axion) phase, and finally to a hidden Weyl phase as the pump fluence increases. Other distinguishing features corroborating with the light-induced switchings include: mode-selective coupling of coherent phonons to polaron and CDW modulation, and the emergence of a {\em non-thermal} chiral photocurrent above pump threshold of CDW-related phonons. The ultrafast chirality control of correlated topological states revealed here is important to realize axion electrodynamics and quantum computing.
Comment: 9 pages, 4 figures
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Chirality manipulation of ultrafast phase switchings in a correlated CDW-Weyl semimetal
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Autor/in / Beteiligte Person: | Cheng, Bing ; Cheng, Di ; Jiang, Tao ; Xia, Wei ; Song, Boqun ; Mootz, Martin ; Luo, Liang ; Perakis, Ilias E. ; Yao, Yongxin ; Guo, Yanfeng ; Wang, Jigang |
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Quelle: | Nature Communications 15, 785 (2024); (2023) |
Veröffentlichung: | 2023 |
Medientyp: | report |
DOI: | 10.1038/s41467-024-45036-1 |
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