# Topology-Induced Symmetry Breaking for Vortex with Artificial Monopole

## TL;DR

This paper proposes a method to create artificial monopoles and vortices in cold atom systems on a spherical surface, revealing topology-induced symmetry breaking and potential applications in quantum storage.

## Contribution

It introduces a novel way to engineer topological states with arbitrary Chern numbers in cold atoms using laser beams, demonstrating topology-induced symmetry breaking and quantum degeneracy.

## Key findings

- Topology-induced symmetry breaking occurs for odd Chern numbers.
- Ground state degeneracy is protected by topology, enabling stable qubits.
- Method allows control of Chern number via laser modes.

## Abstract

We construct an artificial U(1) gauge field in the cold atom system to form a monopole along with vortices. It is supposed that the cold atoms are confined on a spherical surface, and two sets of identical laser beams in the opposite propagating directions shine on two sides of the sphere. Arbitrary Chern number CN, proportional to the quantized magnetic flux, can be obtained by selecting proper laser modes. This construction meets the condition of Chern's theorem, so that the vortices of the atom wave function will emerge on the sphere, whose winding number equals CN. It is found that a geometric symmetry is broken spontaneously for odd CN, which corresponds to a topology-induced quantum phase transition. In particular for CN=1, the ground state of the cold atoms are double-degenerate and can be applied to make a stable qubit. Since the ground-state degeneracy is protected by topology-induced symmetry breaking against dissipation, the proposed topological structure has vast potential in quantum storage.