Mott Phase in Polarized Two-component Atomic Fermi Lattice Gas:A Playground for S=1/2 Heisenberg Model in Magnetic Field

TL;DR

This paper explores how population imbalance affects Mott phases in 1D two-component Fermi gases in optical lattices, revealing they can simulate S=1/2 Heisenberg models under magnetic fields.

Contribution

It demonstrates that Mott phases in imbalanced Fermi gases can be effectively described by the S=1/2 antiferromagnetic Heisenberg model in a magnetic field.

Findings

Density profiles match Heisenberg chain predictions.

Features from weak to full polarization are captured.

Mott phases serve as platforms for spin system studies.

Abstract

We investigate effects of pseudo-spin population imbalance on Mott phases in 1D trapped two-component atomic Fermi gases loaded on optical lattices based on the repulsive Hubbard model in harmonic traps. By using the density matrix renormalization group method, we numerically calculate density profiles of each component and clarify the pseudo-spin magnetism. Consequently, we find that all the features from weakly imbalance to fully polarized cases are well described by S=1/2 antiferromagnetic Heisenberg chain under magnetic field. These results indicate that the Mott phases offer experimental stages for studying various interacting spin systems.