Retainable Superconductivity and Structural Transition in 1T-TaSe 2 Under High Pressure.

Research paper by Tao T Lin, Xiaojun X Wang, Xin X Chen, Xiaobing X Liu, Xuan X Luo, Xue X Li, Xiaoling X Jing, Qing Q Dong, Bo B Liu, Hanyu H Liu, Quanjun Q Li, Xuebin X Zhu, Bingbing B Liu

Indexed on: 17 Aug '21Published on: 22 Jul '21Published in: Inorganic Chemistry


As a prominent platform possessing the properties of superconductivity (SC) and charge density wave (CDW), transition-metal dichalcogenides (TMDCs) have attracted considerable attention for a long time. Moreover, extensive efforts have been devoted for exploring the SC and/or the interplay between SC and CDW in TMDCs in the past few decades. Here, we systematically investigate the electronic properties and structural evolution of 1T-TaSe under pressure. With increasing pressure, pressure-induced superconductivity is observed at ∼2.6 GPa. The superconductive transition temperature () increases with the suppression of the CDW state to the maximum value of ∼5.1 K at 21.8 GPa and then decreases monotonously up to the highest pressure of 57.8 GPa. 1T-TaSe transforms into a monoclinic 2/ structure above 19 GPa. The monoclinic phase coexists with the original phase as the pressure is released under ambient conditions and the retainable superconductivity with = 2.9 K is observed in the released sample. We suggest that the retained superconductivity can be ascribed to the retention of the superconductive high-pressure monoclinic phase in the released sample. Our findings demonstrate that both the structure and CDW order are related to the superconductivity of TaSe.