Phase Diagram of Spin-3/2 Fermions in One Dimensional Optical Lattices

TL;DR

This study uses DMRG to map the phase diagram of spin-3/2 fermions in 1D optical lattices, revealing various competing orders and the effects of anisotropy on phase stability.

Contribution

It provides the first comprehensive phase diagram for SU(4) symmetric spin-3/2 fermions including effects of single-ion anisotropy.

Findings

Identification of stable FFLO, trion, and quartet phases.

Single-ion anisotropy stabilizes a generalized S=2 bosonic phase.

Detailed phase boundaries and order competition near half-filling.

Abstract

We present a density matrix renormalization group(DMRG) study of a generalized Hubbard chain describing effective spin S=3/2 fermions in an optical lattice.We determine the full phase diagram for the SU(4) symmetric case, and in the presence of single-ion anisotropy in terms of density and polarization.We investigate the stability and competition between different orders, such as quintet Fulde-Ferrell-Larkin-Ovchinnikov(FFLO) pairing, trion and quartet formation, and spin and atomic density waves.Notably, near half-filling, single-ion anisotropy stabilizes a correlated phase that can be understood in terms of a generalized S=2 bosonic t-J chain.