Detecting the entanglement of vortices in ultracold bosons with artificial gauge fields

TL;DR

This paper investigates vortex entanglement in a 2D Bose-Hubbard model with artificial gauge fields, proposing a detection scheme via quantum interference and suggesting potential for quantum memory applications.

Contribution

It introduces an effective Hamiltonian for vortex spin interactions and demonstrates a feasible quantum memory scheme using vortex coherence.

Findings

Vortex entanglement can be detected through quantum interference.

Coherent bosons in vortex cores can serve as qubits.

The scheme is robust against vortex pinning strength variations.

Abstract

The entanglement of vortices in a two-dimensional Bose-Hubbard model with artificial gauge fields is investigated using the exact diagonalization techniques. We propose an effective Hamiltonian for the spin-spin interactions between vortices responsible for this entanglement, and show that the entanglement can be detected through the quantum interference of the bosons in the vortex centers achieved using the Raman coupling and the quantum gas microscope. The strong bosonic coherence between the vortex centers originates from the charge-density wave order in the vortex core. It is robust against the varying of the pinning strength for the vortices to a wide range, and the coherent bosons can be viewed as a qubit stored in the ground state of the system. Our proposal provides a feasible scheme of quantum memory for storing qubits useful in quantum computation.