Interaction induced mergence of Dirac points in Non-Abelian optical lattices

Abstract

We study the properties of an ultracold Fermi gas loaded in a square optical lattice and subjected to an external and classical non-Abelian gauge field. We calculate the energy spectrum of the system and show that the Dirac points in the energy spectrum will remain quite stable under onsite interaction of certain strength. Once the on-site interaction grows stronger than a critical value, the Dirac points will no longer be stable and merge into a single hybrid point. This mergence implies a quantum phase transition from a semimetallic phase to a band insulator. The on-site interaction between ultracold fermions could be conveniently controlled by Feshbach resonances in current experiments. We proposed that this remarkable interaction induced mergence of Dirac points may be observed in the ultracold fermi gas experiments.

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Cited by in corpus (8)

• Ultracold Spin-Orbit Coupled Bose-Einstein Condensate in a Cavity: Route to Magnetic Phases Through Cavity Transmission
• Coupling, merging, and splitting Dirac points by electron-electron interaction
• Topological phase transitions driven by non-Abelian gauge potentials in optical square lattices
• Spin-orbit-coupled atomic Fermi gases in two-dimensional optical lattices in the presence of a Zeeman field
• Quantum walks accompanied by spin flipping in one-dimensional optical lattices
• Phase diagram, band structure and density of states in two-dimensional attractive Fermi-Hubbard model with Rashba spin-orbit coupling
• Dirac points merging and wandering in a model Chern insulator
• Cavity Optomechanics with Ultra Cold Atoms in Synthetic Abelian and Non-Abelian Gauge Field