Eigenvalues correlations and the distribution of ground state angular momenta for random many-body quantum systems

TL;DR

This paper provides a statistical explanation for the common occurrence of ground states with zero angular momentum in many-body quantum systems with random interactions, using eigenvalue correlations.

Contribution

It introduces a covariance-based analysis to explain ground state angular momentum distributions, applicable to both fermionic and bosonic systems.

Findings

Eigenvalue correlations explain ground state angular momentum distribution.

Method validated on the interacting boson model.

Provides a unified statistical framework for quantum systems.

Abstract

The observed preponderance of ground states with angular momentum L=0 in many-body quantum systems with random two-body interactions is analyzed in terms of correlation coefficients (covariances) among different eigenstates. It is shown that the geometric analysis of Chau {\it et al.} can be interpreted in terms of correlations (covariances) between energy eigenvalues thus providing an entirely statistical explanation of the distribution of ground state angular momenta of randomly interacting quantum systems which, in principle, is valid for both fermionic and bosonic systems. The method is illustrated for the interacting boson model.