Antiferromagnetic Order of Strongly Interacting Fermions in a Trap: Real-Space Dynamical Mean-Field Analysis

TL;DR

This paper uses Real-Space Dynamical Mean-Field Theory to study antiferromagnetic order in strongly interacting spin-1/2 fermions within a harmonic trap, revealing stability near half filling and suppression with spin imbalance.

Contribution

It introduces a R-DMFT approach to analyze spatially inhomogeneous antiferromagnetic states in trapped fermionic systems, highlighting new stability and phase separation phenomena.

Findings

Antiferromagnetic order is stable near half filling in the trap.

Order persists even with local density deviations from half filling.

Spin imbalance suppresses antiferromagnetism and induces phase separation.

Abstract

We apply Dynamical Mean-Field Theory to strongly interacting fermions in an inhomogeneous environment. With the help of this Real-Space Dynamical Mean-Field Theory (R-DMFT) we investigate antiferromagnetic states of repulsively interacting fermions with spin 1/2 in a harmonic potential. Within R-DMFT, antiferromagnetic order is found to be stable in spatial regions with total particle density close to one, but persists also in parts of the system where the local density significantly deviates from half filling. In systems with spin imbalance, we find that antiferromagnetism is gradually suppressed and phase separation emerges beyond a critical value of the spin imbalance.