A Fully Self-Consistent Treatment of Collective Fluctuations in Quantum Liquids

TL;DR

This paper develops a fully quantum mechanical, self-consistent mode-coupling theory to analyze collective density fluctuations in quantum liquids, offering semi-quantitative insights into their dynamics and relevance to quantum glassy systems.

Contribution

It introduces a novel quantum mode-coupling approach that improves understanding of collective fluctuations in quantum liquids compared to previous methods.

Findings

Semi-quantitative agreement with experimental data

Effective description of short and long time dynamics

Potential applications to quantum glassy systems

Abstract

The problem of calculating collective density fluctuations in quantum liquids is revisited. A fully quantum mechanical self-consistent treatment based on a quantum mode-coupling theory [E. Rabani and D.R. Reichman, J. Chem. Phys.116, 6271 (2002)] is presented. The theory is compared with the maximum entropy analytic continuation approach and with available experimental results. The quantum mode-coupling theory provides semi-quantitative results for both short and long time dynamics. The proper description of long time phenomena is important in future study of problems related to the physics of glassy quantum systems, and to the study of collective fluctuations in Bose fluids.