Equations of state from individual one-dimensional Bose gases

TL;DR

This paper measures the equation of state of individual 1D Bose gases using in-situ density profiles and compares the results with exact theoretical solutions, revealing insights into cooling and degeneracy.

Contribution

It demonstrates a method to experimentally determine the equation of state of 1D Bose gases and validates it against exact Yang-Yang solutions.

Findings

Agreement with Yang-Yang thermodynamics

Inefficient evaporative cooling reduces temperature and degeneracy

Method enables precise in-situ measurements of 1D quantum gases

Abstract

We trap individual 1D Bose gases and obtain the associated equation of state by combining calibrated confining potentials with in-situ density profiles. Our observations agree well with the exact Yang-Yang 1D thermodynamic solutions under the local density approximation. We find that our final 1D system undergoes inefficient evaporative cooling that decreases the absolute temperature, but monotonically reduces a degeneracy parameter.