Understanding many-body physics in one dimension from the Lieb-Liniger model

TL;DR

This paper introduces the Lieb-Liniger model, an exactly solvable one-dimensional Bose gas, highlighting its rich many-body physics, mathematical integrability, and recent experimental confirmations of its theoretical predictions.

Contribution

It provides an elementary overview of the Lieb-Liniger model's many-body phenomena, integrability, and experimental relevance, emphasizing its fundamental role in quantum physics.

Findings

Experimental observations align with theoretical predictions.

The model exhibits rich quantum many-body physics.

Recent experiments confirm the model's integrability and universality.

Abstract

This article presents an elementary introduction on various aspects of the prototypical integrable model the Lieb-Liniger Bose gas ranging from the cooperative to the collective features of many-body phenomena [1]. In 1963 Lieb and Liniger first solved this quantum field theory many-body problem using the Bethe's hypothesis, i.e. a particular form of wave function introduced by Bethe in solving the one-dimensional Heisenberg model in 1931. Despite the Lieb-Liniger model is arguably the simplest exactly solvable model, it exhibits rich quantum many-body physics in terms of the aspects of mathematical integrability and physical universality. Moreover, the Yang-Yang grand canonical ensemble description for the model provides us with a deep understanding of quantum statistics, thermodynamics and quantum critical phenomena at the many-body physics level. Recently, such fundamental physics of this exactly solved model has been attracting growing interest in experiments. Since 2004, there have been more than 20 experimental papers that report novel observations of different physical aspects of the Lieb-Liniger model in the lab. So far the observed results to date are seen to be in excellent agreement with results obtained using the analysis of this simplest exactly solved model. Those experimental observations reveal the unique beauty of integrability.