Intrinsically interacting higher-order topological superconductors
Haoran Zhang, Jian-Hao Zhang, Zheng‐Cheng Gu, Rui-Xing Zhang, Shuo Yang
Abstract
We propose a minimal interacting lattice model for two-dimensional class-$D$ higher-order topological superconductors with no free-fermion counterpart. A Lieb-Schultz-Mattis-type constraint has been proposed and applied to guide our lattice model construction. Our model exhibits a trivial product ground state in the weakly interacting regime, whereas, increasing electron correlations provoke a novel topological quantum phase transition to a ${D}_{4}$-symmetric higher-order topological superconducting state. The symmetry-protected Majorana corner modes are numerically confirmed with the matrix-product-state technique. Our theory paves the way for studying correlated higher-order topology with explicit lattice model constructions.