Dynamic Density Response of Trapped Interacting Quantum Gases

TL;DR

This paper derives a simplified expression for the dynamic density response function of an interacting quantum gas within RPA, highlighting its relevance for Bragg scattering measurements and other applications.

Contribution

It introduces a new analytical expression for the density response function of trapped interacting quantum gases, including first order self and exchange effects.

Findings

Provides a simplified form for the response function when considering diagonal elements.

Connects the response function to measurable Bragg scattering cross-sections.

Highlights the importance of the imaginary part of the response function in experiments.

Abstract

An expression for the dynamic density response function has been obtained for an interacting quantum gas in Random Phase Approximation (RPA) including first order self and exchange contribution. It involves the single particle wave functions and eigen values. The expression simplifies when diagonal elements are considered. The diagonal elements of the imaginary part of Fourier transformed response function is relevant in the measurement of Bragg scattering cross-section and in several other applications.