Topological-Fermi-Liquid to Quantum-Hall-Liquid Transitions: $p$-Band and $d$-Band Fermions in a Magnetic Field

TL;DR

This paper explores topological quantum phase transitions in multi-orbital fermionic systems under magnetic fields, revealing transitions between different quantum Hall states and Fermi liquids, with potential realizations in ultracold atoms and transition metals.

Contribution

It demonstrates topological quantum phase transitions induced by orbital polarization in multi-orbital systems, connecting theoretical models with experimental realizations in ultracold atoms and transition metals.

Findings

Hall conductance exhibits various topological quantum phase transitions

Identification of integer quantum Hall plateau transitions

Transition from topological Fermi liquid to IQH states

Abstract

We find that in a multi-orbital system with intraorbital and interorbital hopping integrals, the Hall conductance exhibits various topological quantum phase transitions (QPTs) induced by on-site orbital polarization: integer quantum Hall (IQH) plateau transitions, and topological Fermi liquid to IQH transitions. Such topological QPTs are demonstrated in two systems: a $p$-band spinless fermionic system realizable with ultracold atoms in optical lattice, and a $d$-band spinful fermionic system closely related to giant orbital Hall effects in transition metals and their compounds.