High-fidelity cluster state generation for ultracold atoms in an optical lattice

TL;DR

This paper introduces a scalable method for generating high-fidelity multipartite entanglement in ultracold atoms within optical lattices, leveraging extra degrees of freedom to optimize quantum operations for measurement-based quantum computing.

Contribution

The authors propose a novel approach that actively uses usually neglected degrees of freedom in the Hubbard model to enhance entanglement fidelity and scalability in ultracold atom systems.

Findings

Achieves high-fidelity multipartite entanglement

Shortens operation time for quantum gates

Maintains scalability despite stronger interactions

Abstract

We propose a method for generating high-fidelity multipartite spin-entanglement of ultracold atoms in an optical lattice in a short operation time with a scalable manner, which is suitable for measurement-based quantum computation. To perform the desired operations based on the perturbative spin-spin interactions, we propose to actively utilize the extra degrees of freedom (DOFs) usually neglected in the perturbative treatment but included in the Hubbard Hamiltonian of atoms, such as, (pseudo-)charge and orbital DOFs. Our method simultaneously achieves high fidelity, short operation time, and scalability by overcoming the following fundamental problem: enhancing the interaction strength for shortening operation time breaks the perturbative condition of the interaction and inevitably induces unwanted correlations among the spin and extra DOFs.