Particle partition entanglement of bosonic Luttinger liquids

TL;DR

This paper studies the particle bipartition entanglement entropy in bosonic Luttinger liquids, revealing a universal logarithmic scaling with system size determined solely by the Luttinger parameter, confirmed through quantum Monte Carlo simulations.

Contribution

It demonstrates that the leading order finite-size scaling of particle bipartition entanglement entropy depends only on the Luttinger parameter, contrasting with spatial bipartition results.

Findings

Leading order scaling is logarithmic in system size.

Prefactor of the scaling is the inverse Luttinger parameter.

Quantum Monte Carlo confirms theoretical predictions.

Abstract

We consider the R\'{e}nyi entanglement entropy of bosonic Luttinger liquids under a particle bipartition and demonstrate that the leading order finite-size scaling is logarithmic in the system size with a prefactor equal to the inverse Luttinger parameter. While higher order corrections involve a microscopic length scale, the leading order scaling depends only on this sole dimensionless parameter which characterizes the low energy quantum hydrodynamics. This result contrasts the leading entanglement entropy scaling under a spatial bipartition, for which the coefficient is universal and independent of the Luttinger parameter. Using quantum Monte Carlo calculations, we explicitly confirm the scaling predictions of Luttinger liquid theory for the Lieb-Liniger model of $\delta$-function interacting bosons in the one dimensional spatial continuum.