Adiabatic nonlinear probes of one-dimensional Bose gases

TL;DR

This paper explores how adiabatic processes in one-dimensional Bose gases, modeled by the sine-Gordon model, reveal interaction-dependent excitations and nonlinear responses useful for characterizing such quantum systems.

Contribution

It introduces a method to analyze nonlinear adiabatic responses in 1D Bose gases using the sine-Gordon model, highlighting the interaction sensitivity of excitation scaling.

Findings

Power-law scaling of excitations with ramping rate

Response varies with interaction strength

Nonlinear response characterizes system properties

Abstract

We discuss two complementary problems: adiabatic loading of one-dimensional bosons into an optical lattice and merging two one-dimensional Bose systems. Both problems can be mapped to the sine-Gordon model. This mapping allows us to find power-law scalings for the number of excitations with the ramping rate in the regime where the conventional linear response approach fails. We show that the exponent of this power law is sensitive to the interaction strength. In particular, the response is larger, or less adiabatic, for strongly (weakly) interacting bosons for the loading (merging) problem. Our results illustrate that in general the nonlinear response to slow relevant perturbations can be a powerful tool for characterizing properties of interacting systems.