Topological Kondo insulators in one dimension: Continuous Haldane-type ground state evolution from the strongly-interacting to the non-interacting limit

LISANDRINI, FRANCO THOMAS; ALEJANDRO M. LOBOS; CLAUDIO J. GAZZA; ARIEL O. DOBRY

PHYSICAL REVIEW B

AMER PHYSICAL SOC

Lugar: New York; Año: 2017 vol. 96

1098-0121

We study, by means of the density-matrix renormalization group (DMRG)technique, the evolution of the ground state in a one-dimensionaltopological insulator, rom the non-interacting to the strongly-interactinglimit, where the system can be mapped onto a topological Kondo-insulatormodel. We focus on a toy model Hamiltonian (i.e., the interacting "sp-ladder" model), which could be experimentally realized in optical latticeswith higher orbitals loaded with ultra-cold fermionic atoms. Our goalis to shed light on the emergence of the strongly-interacting groundstate and its topological classification as the Hubbard-U interaction parameter of the model is increased. Our numerical results show thatthe ground state can be generically classified as a symmetry-protectedtopological phase of the Haldane-type, even in the non-interactingcase U=0 where the system can be additionally classified as a time-reversal Z2-topological insulator, and evolves adiabaticallybetween the non-interacting and strongly interacting limits.