Temperature in One-Dimensional Bosonic Mott insulators

TL;DR

This paper investigates the temperature effects in one-dimensional bosonic Mott insulators using a Bose-Hubbard model and continuous unitary transformations, providing insights into excitation spectra and experimental observations.

Contribution

It introduces a method to analyze the spectral properties and temperature effects in 1D bosonic Mott insulators, explaining experimental results with quantitative predictions.

Findings

Quantitative spectral weights for low-energy excitations

Evidence of significant temperature effects at microscopic scales

Explanation of recent Bragg spectroscopy experiments

Abstract

The Mott insulating phase of a one-dimensional bosonic gas trapped in optical lattices is described by a Bose-Hubbard model. A continuous unitary transformation is used to map this model onto an effective model conserving the number of elementary excitations. We obtain quantitative results for the kinetics and for the spectral weights of the low-energy excitations for a broad range of parameters in the insulating phase. By these results, recent Bragg spectroscopy experiments are explained. Evidence for a significant temperature of the order of the microscopic energy scales is found.