Floquet second-order topological insulators in non-Hermitian systems

Second-order topological insulator (SOTI) is featured with the presence of $(d-2)$-dimensional boundary states in $d$-dimension systems. The non-Hermiticity induced breakdown bulk-boundary correspondence (BBC) and periodic driving on systems generally obscure description non-Hermitian SOTI. To prompt applications SOTIs, we explore role controllably creating exotic SOTIs both for 2D 3D A scheme to retrieve BBC a complete via bulk topology such nonequilibrium are proposed. It found that rich widely tunable number corner hinge coexistence first- second-order insulators by driving. Enriching family phases, our result may inspire exploration apply tuning corner/hinge