First-order topological quantum phase transition in a strongly correlated ladder
Simone Barbarino, Giorgio Sangiovanni, Jan Carl Budich
We report on the discovery of a quantum tricritical point (QTP) separating a line of first-order topological quantum phase transitions from a continuous transition regime in a strongly correlated one-dimensional lattice system. Specifically, we study a fermionic four-leg ladder supporting a symmetry-protected topological insulator phase in the presence of on-site interaction, which is driven towards a trivial gapped phase by a nearest-neighbor interaction. Based on DMRG simulations, we show that, as a function of the interaction strength, the phase transition between the topological and the trivial phase switches from being continuous to exhibiting a first-order character. Remarkably, the QTP as well as the first-order character of the topological transition in the strongly correlated regime are found to clearly manifest in simple local observables.
arXiv:1812.01045•Physical review. B./Physical review. B•Feb 27, 2019•24 citations