Interaction-driven topological phase transitions in fermionic SU($3$) systems

TL;DR

This paper explores how interactions and potentials induce various topological and magnetic phases in SU(3) fermionic systems on a triangular lattice, revealing multiple phase transitions driven by Hubbard interactions and sublattice potentials.

Contribution

It identifies and characterizes new interaction-driven topological and magnetic phase transitions in SU(3) fermions, including the emergence of a charge-ordered magnetic insulator.

Findings

Hubbard interaction transforms QHI into magnetic Mott insulator.

Two phase transitions occur with increasing Hubbard interaction at intermediate TSP.

Charge-ordered magnetic insulator appears at large TSP, leading to a new transition.

Abstract

We consider SU($3$) fermions on the triangular lattice in the presence of a gauge potential which stabilizes a quantum Hall insulator (QHI) at the density of one particle per lattice site. We investigate the effect of the Hubbard interaction, favoring magnetic long-range order, and a three-sublattice potential (TSP), favoring a normal insulator (NI), on the system. For weak TSP we find that the Hubbard interaction drives the QHI into a three-sublattice magnetic Mott insulator (MMI). For intermediate values of TSP we identify two transition points upon increasing the Hubbard interaction. The first transition is from the NI to the QHI and the second transition is from the QHI to the MMI. For large values of the TSP a charge-ordered magnetic insulator (COMI) emerges between the NI and the QHI, leading to an interaction-driven COMI-to-QHI transition.