Disorder induced multifractal superconductivity in monolayer niobium dichalcogenides
Abstract
The interplay between disorder and superconductivity is a subtle and fascinating phenomenon in quantum many body physics. The conventional superconductors are insensitive to dilute nonmagnetic impurities, known as the Anderson's theorem. Destruction of superconductivity and even superconductor-insulator transitions occur in the regime of strong disorder. Hence disorder-enhanced superconductivity is rare and has only been observed in some alloys or granular states. Because of the entanglement of various effects, the mechanism of enhancement is still under debate. Here we report well-controlled disorder effect in the recently discovered monolayer NbSe superconductor. The superconducting transition temperatures of NbSe monolayers are substantially increased by disorder. Realistic theoretical modeling shows that the unusual enhancement possibly arises from the multifractality of electron wave functions. This work provides the first experimental evidence of the multifractal superconducting state.
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Cite
@article{arxiv.1904.07076,
title = {Disorder induced multifractal superconductivity in monolayer niobium dichalcogenides},
author = {Kun Zhao and Haicheng Lin and Xiao Xiao and Wantong Huang and Wei Yao and Mingzhe Yan and Ying Xing and Qinghua Zhang and Zi-Xiang Li and Shintaro Hoshino and Jian Wang and Shuyun Zhou and Lin Gu and Mohammad Saeed Bahramy and Hong Yao and Naoto Nagaosa and Qi-Kun Xue and Kam Tuen Law and Xi Chen and Shuai-Hua Ji},
journal= {arXiv preprint arXiv:1904.07076},
year = {2019}
}