Evidence for correlated states in a cluster of bosons with Rashba spin-orbit coupling

TL;DR

This paper investigates the ground state of two-dimensional spin-half bosons with Rashba spin-orbit coupling, revealing strong correlations and favoring non-ideal condensed states through exact diagonalization and effective Hamiltonian analysis.

Contribution

It provides the first detailed analysis of correlated ground states in bosonic systems with Rashba spin-orbit coupling using exact diagonalization and effective Hamiltonian methods.

Findings

Strong correlations in the ground state due to enhanced low-energy density of states

Correlated states are energetically favored over ideal condensed states

Effective Hamiltonian explains the emergence of correlated ground states

Abstract

We study the ground state properties of spin-half bosons subjected to the Rashba spin-orbit coupling in two dimensions. Due to the enhancement of the low energy density of states, it is expected that the effect of interaction becomes more important. After reviewing several possible ideal condensed states, we carry out an exact diagonalization calculation for a cluster of the bosons in the presence of strong spin-orbit coupling on a two-dimensional disk and reveal strong correlations in its ground state. We derive a low-energy effective Hamiltonian to understand how states with strong correlations become energetically more favorable than the ideal condensed states.