Quantum Cellular Automata on a Dual-Species Rydberg Processor

TL;DR

This paper demonstrates the experimental realization of quantum cellular automata on a dual-species Rydberg atom array, showcasing scalable global control for complex quantum protocols and many-body dynamics.

Contribution

It introduces the first experimental implementation of QCAs with dual-species Rydberg atoms, utilizing independent global controls to perform diverse quantum protocols and generate high-fidelity entangled states.

Findings

Successful realization of QCAs on a dual-species Rydberg array

Generation of 96.7% fidelity Bell states and 17-qubit cluster states

Demonstration of scalable global control enabling complex quantum dynamics

Abstract

As quantum devices scale to larger and larger sizes, a significant challenge emerges in scaling their coherent controls accordingly. Quantum cellular automata (QCAs) constitute a promising framework that bypasses this control problem: universal dynamics can be achieved using only a static qubit array and global control operations. Despite an extensive history of theoretical explorations and proposals, QCAs have not been experimentally explored in the context of highly-scalable globally-controlled systems. Here we realize QCAs on a dual-species Rydberg array of rubidium and cesium atoms, leveraging independent global control of each species to perform multiple quantum protocols. Seeding an automaton with different initial states, we explore many-body dynamics of quasiparticles and grow GHZ states across both species, highlighting the flexibility of our approach. We further develop a second automaton using a novel mediated entangling gate, enabling generation of 96.7(1.7)%-fidelity Bell states, 17-qubit cluster states, and high-connectivity graph states. Our results demonstrate that simple global controls enable access to a rich variety of applications through the QCA framework. The versatility and scalability of QCAs present compelling opportunities for the development of quantum information systems, as well as new perspectives on quantum many-body dynamics.