# Bosonic Weyl excitations induced by $p$-orbital interactions in a cubic optical lattice

## TL;DR

This paper proposes a novel scheme to realize interaction-induced Weyl points in bosonic superfluids within a 3D optical lattice, revealing topologically protected excitations analogous to electronic Weyl semimetals.

## Contribution

It introduces a method to generate Weyl points for bosonic Bogoliubov excitations via $p$-orbital interactions in a cubic optical lattice, a first in bosonic systems.

## Key findings

- Interaction-induced Weyl points in bosonic superfluids
- Topologically protected edge modes in the superfluid
- Time-reversal symmetry breaking due to $p$-orbital interactions

## Abstract

Weyl points exist in a fascinating topological state of matter with linear band crossings analogous to magnetic monopoles. Tremendous efforts have been devoted to investigate fermionic topological matters with Weyl points in the single-particle band dispersion. It remains elusive for realizing interaction-induced Weyl points, especially for bosons. Motivated by recent experimental progress in ultracold atoms, we propose a scheme to create Weyl points for Bogoliubov excitations of a bosonic superfluid in a three-dimensional cubic optical lattice. The unique design of the lattice leads to interaction-induced time-reversal symmetry breaking for a $p$-orbital superfluid, which in turn induces Weyl Bogoliubov excitations. Analogous to Weyl semimetals of electronic systems, the superfluid also support topologically protected edge modes due to the bulk-boundary correspondence.