A Coherent Quantum Annealer with Rydberg Atoms

TL;DR

This paper proposes a new platform for quantum annealing using Rydberg atoms and the LHZ architecture, enabling coherent adiabatic quantum computation with all-to-all interactions.

Contribution

It combines Rydberg atom quantum simulation with the LHZ architecture to create a prototype for a coherent quantum annealer with all-to-all Ising interactions.

Findings

Rydberg atoms can emulate the LHZ spin model with quasi-local 4-body constraints.

Laser-dressed Rydberg interactions are much larger than decoherence rates.

The platform enables exploration of quantum optimization protocols with current atomic physics technology.

Abstract

There is a significant ongoing effort in realizing quantum annealing with different physical platforms. The challenge is to achieve a fully programmable quantum device featuring coherent adiabatic quantum dynamics. Here we show that combining the well-developed quantum simulation toolbox for Rydberg atoms with the recently proposed Lechner-Hauke-Zoller~(LHZ) architecture allows one to build a prototype for a coherent adiabatic quantum computer with all-to-all Ising interactions and, therefore, a novel platform for quantum annealing. In LHZ a infinite-range spin-glass is mapped onto the low energy subspace of a spin-1/2 lattice gauge model with quasi-local 4-body parity constraints. This spin model can be emulated in a natural way with Rubidium and Cesium atoms in a bipartite optical lattice involving laser-dressed Rydberg-Rydberg interactions, which are several orders of magnitude larger than the relevant decoherence rates. This makes the exploration of coherent quantum enhanced optimization protocols accessible with state-of-the-art atomic physics experiments.