Non-Luttinger quantum liquid of one-dimensional spin-orbit-coupled bosons

Abstract

We show that the synthetic spin-orbit coupling created in current ultracold atom experiments provides physicists a unique tool to control the Luttinger liquid parameter $K$ of weakly interacting bosons in one dimension. At a critical value of the Raman coupling strength ${\ensuremath{\Omega}}_{c}$, $K$ is suppressed down to zero, and the characteristic quasi-long-range order for ordinary one-dimensional quantum systems disappears. Consequently, the single-particle correlation function decays exponentially at the ground state, signifying the rise of a one-dimensional quantum many-body state beyond the standard Luttinger liquid paradigm. Momentum distribution, as well as scaling relations for various quantities in the vicinity of the critical point, can be used as a direct diagnosis of this non-Luttinger quantum liquid.