Ising pairing in superconducting NbSe2 atomic layers

By X. Xi, Zefang Wang, Weiwei Zhao, Ju-Hyun Park, K. T. Law, H. Berger, L. Forr'o, J. Shan, K. Mak. Nature Physics, 2015

1,148 citations recorded by the source corpus.

The superconducting properties of NbSe2 as it approaches the monolayer limit are investigated by means of magnetotransport measurements, uncovering evidence of spin–momentum locking. The properties of two-dimensional transition metal dichalcogenides arising from strong spin–orbit interactions and valley-dependent Berry curvature effects have recently attracted considerable interest1,2,3,4,5,6,7. Although single-particle and excitonic phenomena related to spin–valley coupling have been extensively studied1,3,4,5,6, the effects of spin–valley coupling on collective quantum phenomena remain less well understood. Here we report the observation of superconducting monolayer NbSe2 with an in-plane upper critical field of more than six times the Pauli paramagnetic limit, by means of magnetotransport measurements. The effect can be interpreted in terms of the competing Zeeman effect and large intrinsic spin–orbit interactions in non-centrosymmetric NbSe2 monolayers, where the electron spin is locked to the out-of-plane direction. Our results provide strong evidence of unconventional Ising pairing protected by spin–momentum locking, and suggest further studies of non-centrosymmetric superconductivity with unique spin and valley degrees of freedom in the two-dimensional limit.

Subfields: Atomic and Molecular Physics, and Optics, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/54663f2a971756e4d805451c03d33409edccc735

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

1. Yong Xu
2. K. He
3. Q. Xue
4. Shoucheng Zhang
5. Xiao-Liang Qi
6. Y. Ando
7. Masatoshi Sato
8. Hsin Lin

In Materials Chemistry

1. Yong Xu
2. K. He
3. Q. Xue
4. Kai Liu
5. Yinghui Sun
6. Xuewen Wang
7. Shoucheng Zhang
8. Xiao-Liang Qi

Citations in the corpus

• Chemical and structural stability of 2D layered materials (2019, methodology): “They ascribe the superior stability of these NbSe2 films grown from the pure Nb films to the absence of atomic vacancy and oxygen bonds, which often generate the activated reactive sites in the grown NbSe2 films and accelerate their reaction with H2O and O2.”
• Superconductivity in few-layer stanene (2017, background): “Of late, the realization of highly crystalline and atomically thin superconductors has triggered a flurry of discoveries including the Griffiths singularity behavior [3], a quantum metallic phase [4,5], as well as an extremely large critical magnetic field in the plane [6,7,8].”