Inter-species entanglement of Bose-Bose mixtures trapped in optical lattices

TL;DR

This paper investigates how inter-species entanglement affects the phase transition behavior in Bose-Bose mixtures in optical lattices, revealing that entanglement causes asymmetric shifts in the Mott-insulator lobes.

Contribution

It introduces a perturbative approach based on lattice symmetries to analyze inter-species entanglement effects on the Mott transition in Bose-Bose mixtures.

Findings

Inter-species entanglement causes nonuniform shifts in Mott lobes.

Perturbation theory results agree with quantum Monte Carlo simulations.

Entanglement influences quantum phase transition characteristics.

Abstract

In the present work we discuss inter-species entanglement in Bose-Bose mixtures trapped in optical lattices. This work is motivated by the observation that, in the presence of a second component, the Mott-insulator lobe shifts {\em{differently}} on the hole- and particle-side with respect to the Mott lobe of the single species system (Phys. Rev. A 82, 021601, Laser Phys. 21, 1443). We use perturbation theory, formulated in a Hilbert space decomposed by means of lattice symmetries, in order to show that the nonuniform shift of the Mott lobe is a consequence of an inter-species entanglement which differs in the lowest excited states to remove and add a particle. Our results indicate that inter-species entanglement in mixtures can provide a new perspective in understanding quantum phase transitions. To validate our approach, we compare our results from perturbation theory with quantum Monte Carlo simulations.