Haldane phase in one-dimensional topological Kondo insulators

ALEJANDRO MEZIO; ALEJANDRO LOBOS; ARIEL DOBRY; CLAUDIO GAZZA

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

The American Physical Society

Lugar: Nueva York; Año: 2015 vol. 92 p. 2051281 - 2051289

0163-1829

We investigate the ground-state properties of a recently proposed model for a topological Kondo insulator in onedimension (i.e., the p-wave Kondo-Heisenberg lattice model) by means of the density-matrix renormalizationgroupmethod. The nonstandard Kondo interaction in this model is different from the usual (i.e., local) Kondointeraction in that the localized spins couple to the ?p-wave? spin density of conduction electrons, inducing atopologically nontrivial insulating ground state. Based on the analysis of the charge- and spin-excitation gaps,the string order parameter, and the spin profile in the ground state, we show that, at half filling and low energies,the system is in the Haldane phase and hosts topologically protected spin-1/2 end states. Beyond its intrinsicinterest as a useful ?toy model? to understand the effects of strong correlations on topological insulators, weshow that the p-wave Kondo-Heisenberg model could be experimentally implemented in p-band optical latticesloaded with ultracold Fermi gases.