Odd-parity magnetism by quantum geometry

TL;DR

This paper reveals a geometric mechanism involving the quantum metric of Bloch electrons that drives odd-parity multipole magnetism, offering a new design principle for such magnetic states.

Contribution

It demonstrates how quantum geometry directly influences odd-parity magnetic multipole instabilities in a multi-sublattice model, expanding understanding of quantum-geometric magnetism.

Findings

Quantum metric controls instability toward odd-parity magnetic order.

The magnetic state exhibits complex correlations characteristic of quantum-geometric effects.

The mechanism applies over a wide parameter range and can be induced by Hubbard interaction.

Abstract

We uncover a geometric mechanism of odd-parity multipole magnetism driven by the quantum metric of Bloch electrons. By analyzing spin and odd-parity multipole susceptibilities in a multi-sublattice model, we demonstrate that the quantum metric directly controls the instability toward odd-parity magnetic multipole order over a wide range of parameters, which condenses under Hubbard interaction. The resulting state exhibits complex magnetic correlations, as a hallmark of quantum-geometric magnetism. These results establish a geometric design principle for odd-parity multipole magnets and provide a route toward the experimental verification of quantum-geometric magnetism.