Hybrid-order topological odd-parity superconductors via Floquet engineering

TL;DR

This paper introduces a Floquet engineering approach to create hybrid-order topological superconductors with coexisting edge and corner states, overcoming previous symmetry constraints and enabling new topological phases.

Contribution

It presents a novel Floquet scheme to realize 2D and 3D hybrid-order topological superconductors with coexisting gapless and gapped states, breaking fundamental limitations.

Findings

Created 2D hybrid-order topological phases with coexisting edge and corner states.

Discovered a 3D second-order Dirac superconductor with surface and hinge Majorana Fermi arcs.

Demonstrated that periodic driving can generate topological phases without static counterparts.

Abstract

Having the potential for performing quantum computation, topological superconductors have been generalized to the second-order case. The hybridization of different orders of topological superconductors is attractive because it facilitates the simultaneous utilization of their respective advantages. However, previous studies found that they cannot coexist in one system due to the constraint of symmetry. We propose a Floquet engineering scheme to generate two-dimensional (2D) hybrid-order topological superconductors in an odd-parity superconductor system. Exotic hybrid-order phases exhibiting the coexisting gapless chiral edge states and gapped Majorana corner states not only in two different quasienergy gaps but also in one single quasienergy gap are created by periodic driving. The generalization of this scheme to the 3D system allows us to discover a second-order Dirac superconductor featuring coexisting surface and hinge Majorana Fermi arcs. Our results break a fundamental limitation on topological phases and open a feasible avenue to realize topological superconductor phases without static analogs.