A Rubidium Optical Tweezer Platform for Squeezed-Light-Enhanced Readout and Trapped-Atom Interferometry

Optical tweezers have emerged as a powerful platform for neutral-atom quantum information processing due to their capacity for high-fidelity coherent control and scalability. We present the design and construction of an optical tweezer apparatus for trapping and coherently controlling individual neutral rubidium atoms for applications in quantum computing and precision measurement.

A major challenge for neutral-atom quantum computing is fast, high-fidelity atomic state readout with minimal decoherence. Conventional fluorescence imaging relies on spontaneous photon scattering, which leads to heating and decoherence that limit readout fidelity and speed. We plan to address this limitation through a twofold approach. First, we will use homodyne detection to amplify the weak scattered field with a strong local oscillator to achieve shot-noise-limited measurements. Second, we will integrate squeezed light to enable quantum-enhanced detection with measurement noise reduced below the shot-noise limit. Squeezed-light-assisted readout may enable higher-fidelity state detection for neutral-atom quantum computing.

In parallel, the platform is designed to support a trapped-atom interferometry scheme based on coherently delocalizing single atoms between spatially separated optical tweezers. Starting from a single atom prepared in a spin superposition, a state-dependent optical tweezer will be used to spatially separate the atomic wavefunction into two distinct locations, creating a spatial superposition. The two wavepackets will be held at a fixed separation for a variable interrogation time before being recombined, mapping the accumulated phase onto an internal atomic state. These interferometric protocols will provide a benchmark for matter-wave coherence time, phase stability, and control fidelity in the optical tweezer system.