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

Abstract

Nearest neighbour bosons possessing only onsite interactions do not form onsite bound pairs in their quantum walk due to fermionization. We obtain signatures of non-trivial onsite pairing in the quantum walk of strongly interacting two component bosons in a one dimensional lattice. By considering an initial state with particles from different components located at the nearest-neighbour sites in the central region of the lattice, we show that in the dynamical evolution of the system, competing intra- and inter-component onsite repulsion leads to the formation of onsite inter-component bound states. We find that when the total number of particles is three, an inter-component pair is favoured in the limit of equal intra- and inter-component interaction strengths. However, when two bosons from each species are considered, inter-component pairs and trimer are favoured depending on the ratios of the intra- and inter-component interactions. In both the cases, we find that the quantum walks exhibit a re-entrant behaviour as a function of inter-component interaction.