Competing orders in one dimensional spin 3/2 fermionic systems

TL;DR

This paper explores various competing quantum orders in one-dimensional spin 3/2 fermionic systems, revealing a quartetting phase, phase transitions, and charge/bond orderings in optical lattices.

Contribution

It introduces the quartetting phase as a novel four-fermion order and analyzes phase transitions driven by Ising symmetry breaking in spin channels.

Findings

Existence of a quartetting phase in a large phase diagram region

Phase transition between quartetting and singlet pairing controlled by Ising symmetry

Identification of charge and bond ordered phases at commensurate fillings

Abstract

Novel competing orders are found in spin 3/2 cold atomic systems in one-dimensional optical traps and lattices. In particular, the quartetting phase, a four-fermion counterpart of Cooper pairing, exists in a large portion of the phase diagram. The transition between the quartetting and singlet Cooper pairing phases is controlled by an Ising symmetry breaking effect in one of the spin channels. The singlet Cooper pairing phase also survives in the purely repulsive interaction regime. In addition, various charge and bond ordered phases are identified at commensurate fillings in lattice systems.