Topological orbital superfluid with chiral d-wave order in a rotating optical lattice

TL;DR

This paper predicts a topological orbital superfluid with chiral d-wave pairing in a rotating optical lattice, featuring multiple edge modes and observable mass currents, advancing understanding of exotic quantum states.

Contribution

It introduces a novel topological superfluid phase driven by rotation-induced hybridization and chiral pairing in a multi-orbital optical lattice, with experimentally verifiable signatures.

Findings

Supports four chiral Andreev edge modes

Rotation induces inter-orbital hybridization leading to topological order

Confining potential creates detectable mass currents

Abstract

Topological superfluid is an exotic state of quantum matter that possesses a nodeless superfluid gap in the bulk and Andreev edge modes at the boundary of a finite system. Here, we study a multi-orbital superfluid driven by attractive s-wave interaction in a rotating optical lattice. Interestingly, we find that the rotation induces the inter- orbital hybridization and drives the system into topological orbital superfluid in accordance with intrinsically chiral d-wave pairing characteristics. Thanks to the conservation of spin, the topological orbital superfluid supports four rather than two chiral Andreev edge modes at the boundary of the lattice. Moreover, we find that the intrinsic harmonic confining potential forms a circular spatial barrier which accumulates atoms and supports a mass current under injection of small angular momentum as external driving force. This feature provides an experimentally detectable phenomenon to verify the topological orbital superfluid with chiral d-wave order in a rotating optical lattice.