Gate-based Readout and Cooling of Neutral Atoms

TL;DR

This paper presents an ancilla-based toolbox for neutral atom experiments that improves readout fidelity, detects atom loss mid-circuit, and cools atoms, addressing key hardware challenges in quantum technologies.

Contribution

It introduces new methods for high-fidelity atom readout, mid-circuit loss detection, and algorithmic cooling using ancilla atoms and Rydberg gates in optical tweezer setups.

Findings

Enhanced detection fidelity over multiple readout rounds

Successful mid-circuit atom loss detection without disturbing data atoms

Effective algorithmic cooling reducing atomic temperature

Abstract

Neutral atom arrays have seen tremendous progress in quantum simulation, quantum metrology, and fault-tolerant quantum computing. However, hardware constraints such as atom loss and heating remain significant challenges. In this work, we introduce a comprehensive ancilla-based toolbox for optical tweezer experiments that utilizes high-fidelity Rydberg entangling gates and ancilla atoms to mitigate these physical limitations. First, we demonstrate repeated ancilla-based atom readout, achieving improved detection fidelity over multiple rounds with minimal perturbation to data atoms. Second, leveraging the quantized motional states in tweezer-trapped strontium atoms, we transduce quantum information from the electronic to the motional manifold. This enables us to perform mid-circuit ancilla-based atom loss detection in a coherence-preserving fashion. Finally, we demonstrate algorithmic cooling, a circuit-based sequence that deterministically cools data atoms by transferring their motional entropy to the electronic states of ancilla atoms. We observe a marked reduction in the atomic temperature of data atoms. These tools offer a pathway to continuous operation in tweezer clocks and complement recent developments in continuous reloading experiments.