Type-II Dirac semimetals exhibit a unique Fermi surface topology, which allows them to host novel topological superconductivity (TSC). We reveal a novel inter-orbital superconducting state, corresponding to the B1u and B2u pairings under the D4h point group. Intriguingly, we find that both first- and second-order TSC coexist in this novel state. It is induced by a dominant inter-orbital attraction and possesses surface helical Majorana cones and hinge Majorana flat bands, spanning the entire z-directed hinge Brillouin zone. Further investigation uncovers that these higher-order hinge modes are robust against the C4z symmetry-breaking perturbation.
@article{arxiv.2303.11729,
title = {Hinge Majorana Flat Band in Type-II Dirac Semimetals},
author = {Yue Xie and Xianxin Wu and Zhong Fang and Zhijun Wang},
journal= {arXiv preprint arXiv:2303.11729},
year = {2024}
}