Signatures of non-trivial pairing in the quantum walk of two-component bosons

Abstract

We investigate the quantum walk in a system of two-component bosons in one dimensional lattice. By considering an initial state with particles from different components residing in the nearestnieghbour sites, we show that the competing intra-and inter-component repulsion leads to the formation of onsite inter-component bound states in the dynamical evolution -a phenomenon which is not favourable in the case of indistinguishable bosons. We obtain that when the total number of particles is three, an inter-component pair is favoured for equal inter-and intra-component interaction strengths. However, when two atoms from each species are considered, apart from the intra-component pairs, the system tends to favour a three particle bound state when the strength of inter-component interaction is half of the intra-component one. Moreover, in the regime of equal interactions both inter-and intra-component pairs are formed. In all the cases, we find that the quantum walks exhibit a re-entrant behaviour as a function of inter-species interaction.