Magnetization and collective excitations of a magnetic dipole fermion gas

TL;DR

This paper investigates the ground states and collective excitations of trapped fermion gases with magnetic dipole moments using a density-matrix approach, revealing magnetization effects and tensor properties in excitation modes.

Contribution

It introduces a density-matrix method to study magnetic dipolar fermion gases, connecting it with Hartree-Fock theory and analyzing magnetization and excitation modes.

Findings

Magnetization appears under strong dipole-dipole interactions.

Tensor properties influence spin-related excitation modes.

The density-matrix approach effectively captures one- and two-body observables.

Abstract

The ground states and collective excitations of trapped Fermion gases consisting of atoms with magnetic dipole moment are studied using a time-dependent density-matrix approach. The advantages of the density-matrix approach are that one-body and two-body observables are directly calculated using one-body and two-body density matrices and that it has a clear relation to the Hartree-Fock (HF) and time-dependent HF theory. The HF calculations show the magnetization of the gases when the dipole-dipole interaction is strong. It is shown that the tensor properties of the dipole-dipole interaction are revealed in the excitation modes associated with spin degrees of freedom.