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arXiv · 2005.11012

The soft-mode phonons mediated unconventional superconductivity in monolayer 1T'-WTe2

Wei Yang·Chong-jie Mo·Shi-Bin Fu·Yu Yang·Fa-Wei Zheng·Xiao-Hui Wang·Yuan-An Liu·Ning Hao·Ping Zhang
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Abstract

Recent experiments have tuned the monolayer 1T'-WTe2 to be superconducting by electrostatic gating. Here, we theoretically study the phonon-mediated superconductivity in monolayer 1T'-WTe2 via charge doping. We reveal that the emergence of soft-mode phonons with specific momentum is crucial to give rise to the superconductivity in electron-doping regime, whereas no such soft-mode phonons and no superconductivity emerge in hole-doping regime. We also find a superconducting dome, which can be attributed to the change of Fermi surface nesting condition as electron doping. By taking into account the experimentally established strong anisotropy of temperature-dependent upper critical field H_{c2} between the in-plane and out-of-plane directions, we show that the superconducting state probably has the unconventional equal-spin-triplet pairing in A_{u} channel of C_{2h} point group. Our studies provide a promising understanding to the doping dependent superconductivity and strong anisotropy of H_{c2} in monolayer 1T'-WTe2.

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Wei Yang, Chong-jie Mo, Shi-Bin Fu, Yu Yang, Fa-Wei Zheng, Xiao-Hui Wang, Yuan-An Liu, Ning Hao, Ping Zhang. 2020-05-22. The soft-mode phonons mediated unconventional superconductivity in monolayer 1T'-WTe2. https://doi.org/10.1103/physrevlett.125.237006

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