A cavity-array microscope for parallel single-atom interfacing

Summary

The authors present a cavity-array microscope: a new resonator geometry that uses microlens-array optics and a shared curved mirror to produce many spatially distinct, high-finesse cavity modes that can interface with single neutral atoms in parallel. The design produces inversion-symmetric (doubled) output ports, wavelength-scale waists, and enables high-fidelity single-atom fluorescence readout across an array. The team demonstrates imaging and trap characterisation, techniques to suppress unwanted double-loading of traps, a barycenter-mounted piezo scheme for robust cavity locking with ~10 kHz bandwidth, and detailed loss and efficiency budgets. Experimental discrimination fidelities are reported around 0.992–0.997 after post-processing. The work highlights routes to scale the approach to many simultaneously degenerate modes and discusses implications for quantum networks, multiplexed readout and cavity-mediated interactions.

Key Points

Introduces a cavity-array microscope that creates many individual cavity modes using a microlens array and a common curved mirror, enabling parallel single-atom interfacing.
Geometry produces two wavelength-scale waists per mode and conjugate outcoupling ports (doubling effect) that require loading-control strategies to avoid paired atom loading.
Imaging post-processing (thresholding and Gaussian smoothing) achieves array-averaged state-discrimination fidelities of 0.992(2) to 0.997(2).
Barycenter-mounted piezo mirror reduces low-frequency mount resonances and enables cavity locking bandwidths of ≈10 kHz, suppressing vibration-induced noise.
Trap depth and frequency characterised across the array; alignment sensitivity and mode degeneracy scaling analysed — micron-scale lens accuracy could allow thousands of degenerate modes at modest finesse.
Data and simulation code are available from the corresponding author on request; cavity ray-tracing code (Palm) is public on GitHub.
Competing interests disclosed: consulting and stock options with Atom Computing by some authors, and a patent on the resonator geometry held by several contributors.

Content summary

The paper details the cavity-array microscope design, experimental implementation and characterisation. Extended data show ray-tracing, detailed schematics, trap and imaging characterisation, mode stability and birefringence, and an imaging-efficiency budget. The cavity modes exhibit a doubling of output ports due to inversion about the curved mirror, which both creates useful conjugate imaging channels and a challenge of two-atom loading that the authors mitigate by tuning trap depth and pulsing during loading. The team develops a piezo mounting method that reduces mount-coupled noise and supports a high locking bandwidth. Quantitative results include mode-splitting analysis, trap-frequency measurements, and EMCCD post-processing routines that produce near-99.7% discrimination under less conservative fits. The paper also provides detailed tables of cavity parameters and internal losses and discusses scaling limits tied to lens positioning accuracy and cavity finesse.

Context and relevance

This work sits at the intersection of cavity QED, neutral-atom tweezer arrays and scalable quantum-network interfaces. Parallel, site-resolved cavity coupling is a promising path to scale readout, nondestructive measurement, and cavity-mediated entanglement for neutral-atom processors and modular quantum systems. The microscope architecture offers a route to multiplexed telecom-band networking and high-throughput interfacing without requiring one cavity per atom or complex nanophotonic integration. The demonstrated stabilisation and imaging fidelity address practical challenges for deploying cavity-mediated operations in larger arrays.

Why should I read this?

If you care about scaling neutral-atom quantum hardware or building cavity-linked quantum interconnects, this paper is a tidy shortcut: it shows a clever optical trick for hooking lots of atoms to cavities at once, explains the real-world engineering needed to make it stable, and gives real numbers for readout fidelity and noise suppression. In short — neat hardware idea, usable results, and clear pointers for scaling.

Author style

Punchy. The team doesn’t just sketch an idea — they build it, measure it and quantify limits. If you’re tracking tangible advances towards multiplexed atom–cavity interfaces or practical quantum-network hardware, the details here matter and are worth digging into.

Source

Source: https://www.nature.com/articles/s41586-025-10035-9

Article meta

Article Date: 28 January 2026
Authors: Adam L. Shaw et al.
Affiliations: Stanford, Stony Brook, Chicago, Harvard, Montana State, etc.
Code/data: available on request (cavity ray-tracing: https://github.com/lksplm/sloppy/)