Berry Phase Enforced Spinor Pairing Order

TL;DR

This paper introduces a new class of topological spinor pairing orders characterized by half-integer monopole charges, leading to unique symmetry, surface states, and fractionalized superfluid velocities.

Contribution

It proposes a novel topological pairing order with half-integer monopole charge, expanding the understanding of exotic spinor superconducting states.

Findings

Demonstrates spinor superconducting orders with monopole charges ±1/2

Features a single gap node and nontrivial surface states

Shows superfluid velocity obeys a fractionalized Mermin-Ho relation

Abstract

We introduce a class of topological pairing orders characterized by a half-integer pair monopole charge, leading to Berry phase enforced half-integer partial wave symmetry. This exotic spinor order emerges from pairing between Fermi surfaces with Chern numbers differing by an odd integer. Using tight-binding models, we demonstrate spinor superconducting orders with monopole charges $\pm 1/2$, featuring a single gap node and nontrivial surface states. Additionally, the superfluid velocity follows a fractionalized Mermin-Ho relation in spatially inhomogeneous pairing orders. The concept extends to spinor density waves and excitons.