Spin-triplet paired Wigner crystal stabilized by quantum geometry

TL;DR

This paper demonstrates that quantum geometry, specifically Berry curvature, can induce a transition to a spin-triplet paired Wigner crystal in two-dimensional electron systems, revealing a new electronic pairing mechanism.

Contribution

It uncovers a novel quantum geometry-driven transition to spin-triplet pairing in Wigner crystals, analyzed through variational states and effective two-electron models.

Findings

Berry curvature induces a transition to spin-triplet pairs.

Spin-triplet pairs carry relative orbital angular momentum m=-1.

Quantum geometry provides a strong-coupling mechanism for pairing.

Abstract

We have used variational states to analyze the effects of band geometry on the two-dimensional Wigner crystal with one and two electrons per unit cell. At sufficiently low electron densities, we find that increasing Berry curvature drives a transition into a crystalline state composed of spin-triplet pairs carrying relative orbital angular momentum $m=-1$. The essential features of this transition are captured by an effective two-electron quantum dot problem in the presence of Berry curvature. Our results point to a purely electronic, strong-coupling mechanism for local spin-triplet pairing in correlated two-dimensional electron systems with quantum geometry.