N\'{e}el transition of lattice fermions in a harmonic trap: a real-space DMFT study

TL;DR

This study investigates the Ne9el magnetic transition in trapped ultracold fermions on a lattice using real-space DMFT, revealing experimentally accessible signatures of antiferromagnetic correlations at strong coupling.

Contribution

It applies real-space DMFT with quantum Monte Carlo to analyze magnetic transitions in trapped fermions, highlighting observable double occupancy signatures.

Findings

Antiferromagnetic correlations are indicated by increased double occupancy at strong coupling.

Signatures of magnetic ordering are detectable above the critical temperature.

Dimensional effects are less significant than previously thought.

Abstract

We study the magnetic ordering transition for a system of harmonically trapped ultracold fermions with repulsive interactions in a cubic optical lattice, within a real-space extension of dynamical mean-field theory (DMFT). Using a quantum Monte Carlo impurity solver, we establish that antiferromagnetic correlations are signaled, at strong coupling, by an enhanced double occupancy. This signature is directly accessible experimentally and should be observable well above the critical temperature for long-range order. Dimensional aspects appear less relevant than naively expected.