Fast measurement of neutral atoms with a multi-atom gate

TL;DR

This paper introduces a rapid, high-fidelity measurement protocol for neutral atom quantum computers using a multi-atom Rydberg gate, significantly reducing measurement time and improving efficiency.

Contribution

It proposes a novel multi-atom measurement scheme employing ancilla atoms and global operations, enabling faster and more robust measurements compared to existing methods.

Findings

Achieves measurement infidelity below 10^{-3} within 6 microseconds with five ancillae.

Enhances photon collection by N-fold using a multi-atom register within a Rydberg blockade.

Requires only global pulses and photon collection, avoiding complex shuttling or optimized pulses.

Abstract

Measurement time represents a critical bottleneck limiting the operational speed of neutral atom quantum computers, as it cannot be accelerated through parallelization like other quantum operations. We present a protocol for fast measurement of neutral atoms based on a new, fast multi-atom Rydberg gate that significantly reduces the measurement integration time and improves the measurement fidelity. Our approach employs a multi-qubit register of $N$ ancilla atoms within a single Rydberg blockade region to measure a single data qubit. This enables an $N$-fold enhancement in photon emission collections, while reducing the measurement's sensitivity to loss. The scheme requires spectral separation between the data qubit and the ancillae, achievable through either a dual-species architecture or a targeted light shift. Beyond this, the scheme is straightforward to implement: it relies only on global pulses, global photon collection, and avoids both atom shuttling and numerically optimized pulses. Simulations of a Cs--Rb platform demonstrate that with only five ancillae ($N=5$), measurement infidelity below $10^{-3}$ within $6\ \mu\text{s}$ is achievable.