Hidden CDW states and insulator-to-metal transition after a pulsed femtosecond laser excitation in layered chalcogenide 1T-TaS2−xSex
In: Science Advances, Jg. 4 (2018-07-01), Heft 7
Online
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Zugriff:
Ultrafast laser excitation of electronic crystals reveals hidden quantum states with new polaron cluster ordering.
The hidden (H) quantum state in 1T-TaS2 has sparked considerable interest in the field of correlated electron systems. Here, we investigate ultrafast switches to stable H charge density wave (H-CDW) states observed in 1T-TaS2−xSex, with x = 0 and 0.5 crystals, upon excitation with a single femtosecond laser pulse. In situ cooling transmission electron microscopy observations, initiated by a single femtosecond laser pumping with a low fluence, reveal a clear transition from a commensurate CDW phase (qC) to a new CDW order with qH = (1 − δ)qC for the H-CDW state (δ = 1/9) accompanied by an evident phase separation. H-CDW domain relaxation then occurs and yields a stable metallic phase under a high-fluence excitation. Furthermore, electrical resistivity measurements show that the notable drop in x = 0 and 0.5 samples associated with the appearance of H-CDW states depend on laser fluence and temperature. These results potentially provide a new perspective on the photodoping mechanism for the emergence of H-CDW states in the 1T-TaS2−xSex family.
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Hidden CDW states and insulator-to-metal transition after a pulsed femtosecond laser excitation in layered chalcogenide 1T-TaS2−xSex
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Autor/in / Beteiligte Person: | Tian, Huanfang ; Li, Jianqi ; Yang, Huaixin ; Sun, Shuaishuai ; Sun, Kai ; Zhu, Chunhui |
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Zeitschrift: | Science Advances, Jg. 4 (2018-07-01), Heft 7 |
Veröffentlichung: | American Association for the Advancement of Science, 2018 |
Medientyp: | unknown |
ISSN: | 2375-2548 (print) |
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