Neutral Atoms Coupled to Optical Microcavities

Neutral Atoms Coupled to Optical Microcavities

Neutral atom arrays are a powerful platform for quantum computing and simulation. Interfacing neutral atoms with optical cavities enables fast, nondestructive qubit readout and high-rate generation of remote entanglement. By developing these interfaces, we aim to connect neutral atom quantum computers into a quantum network.

We couple individual atoms trapped in optical tweezers to state-of-the-art Fabry-Perot microcavities to create a versatile atom-photon interface. Using this platform, we have previously demonstrated strong coupling with cooperativities > 100 and cavity-mediated entanglement protocols with built-in error detection.

Current areas of research:

Novel cavity designs optimized for quantum networking

Cavity platforms for enhanced light-matter interactions require high finesse, efficient photon extraction, and compact optical interfaces. We develop novel, scalable fabrication methods for silicon-based Fabry-Perot microcavities with state-of-the-art performance. By utilizing ultra-smooth silicon micromirrors we realize hybrid devices with high mode matching. Further, we demonstrate a novel silicon microcavity platform based on suspended dielectric membranes, achieving a record finesse of 0.9 million at 780 nm. Our devices, engineered to operate at both near-infrared and telecom wavelengths, enable integration with neutral atom arrays and provide ideal platforms for cavity QED experiments and quantum networking applications.

Telecom quantum networking for neutral atoms

For long-range entanglement, telecom-band photons must be used to minimize loss in optical fibers. 87Rb atoms contain an intrinsic interface to 1530 nm (C-band) photons via the 5P3/2 to 4D5/2 transition. In this project, we aim to realize a quantum network based on this transition by entangling 87Rb hyperfine states directly with photonic time-bin qubits at 1530 nm. Furthermore, telecom-band photons are naturally compatible with the mature field of silicon nanophotonics. This opens the door to on-chip manipulation of the 1530 nm photons, enabling more sophisticated entanglement-distribution architectures.

Coupling atom-arrays to optical microcavities

Interfacing neutral atom arrays with optical microcavities can combine scalable quantum computation and photonic networking capabilities in a single platform. In particular, this architecture opens the door to high-dimensional atom-photon entanglement, a key milestone towards distributed quantum computing.
We currently demonstrate strong coupling of up to six atoms in a single row and are working toward multiplexed atom-photon entanglement generation for faster, higher-dimensional quantum links.

References:

[1] B. Grinkemeyer et al. Error-detected quantum operations with neutral atoms mediated by an optical cavity, Science (2025). (arXiv)

[2] S. W. Ding et al. High finesse buckled micromirrors, Optica (2026). (arXiv)