Magnetic field induced band insulator to Mott insulator transformations in 4-component alkali fermions at half-filling

TL;DR

This paper investigates how external magnetic fields induce phase transitions from band insulator to Mott insulator states in 4-component alkali fermions at half-filling, revealing complex symmetry-breaking phenomena relevant for experiments.

Contribution

It demonstrates the transformation pathways and intermediate topological states in 1D fermionic systems under magnetic fields, a novel insight into quantum phase transitions in multi-component fermions.

Findings

Identification of BI to MI transition pathways

Discovery of intermediate topological states

Potential for experimental realization with $^{40}$K atoms

Abstract

Under the influence of an external magnetic field and spin-changing collisions, the band insulator (BI) state of one-dimensional (1D) s-wave repulsively interacting 4-component fermions at half-filling transforms into Mott insulator (MI) states with spontaneously broken translational symmetry: a dimerized state for shallow lattices and a N{\'e}el state for deep lattices via an intermediate topological state. Since a BI has vanishing entropy per particle, these MI phases could be particularly inviting for experimental realization under the similar conditions as those for $^{40}$K atoms [1], provided the magnetic field is changed adiabatically.