Recent discovery of Ising superconductivity protected against in-plane magnetic field by spin-orbit coupling (SOC) has stimulated intensive research interests. The effect, however, was only expected to appear in two-dimensional (2D) noncentrosymmetric materials with spin-valley locking. In this work, we proposed a new type of Ising superconductivity in 2D materials with Cnz rotational symmetry (n=3,4,6). This mechanism, dubbed as type-II Ising superconductivity, is applicable for centrosymmetric materials. Type-II Ising superconductivity relies on the SOC-induced spin-orbital locking characterized by Ising-type Zeeman-like fields displaying opposite signs for opposing orbitals. We found that type-II Ising superconductivity are most prominent around time-reversal invariant momenta and is not sensitive to inversion symmetry breaking. By performing high-throughput first-principles calculations, about one hundred candidate materials were identified. Our work significantly enriches the physics and materials of Ising superconductor, opening new opportunities for fundamental research and practical applications of 2D materials.
@article{arxiv.1903.06660,
title = {Type-II Ising superconductivity in two-dimensional materials with strong spin-orbit coupling},
author = {Chong Wang and Biao Lian and Xiaomi Guo and Jiahao Mao and Zetao Zhang and Ding Zhang and Bing-Lin Gu and Yong Xu and Wenhui Duan},
journal= {arXiv preprint arXiv:1903.06660},
year = {2019}
}