Mid-circuit measurements and entanglement in tweezer arrays of nuclear spin qubits

Neutral atoms in optical tweezers are a promising quantum science architecture, owing to scalability, programmability and single-site readout. A thriving frontier seeks to expand these capabilities, drawing on the unique properties of more complex atoms. One of them is ytterbium 171: its nuclear spin ½ decoupled from electrons is a native qubit robust to decoherence, while its two valence electrons give rise to narrow-linewidth transitions used for preparation of low-entropy atom arrays and qubit manipulation.

Here, we aim to expand the toolbox with mid-circuit measurements, a central ingredient in quantum error correction. Employing microsecond-scale rotations on the clock transition and tweezer-induced light shifts, we site-selectively shelve a subset of qubits to the metastable state and measure the remainder; we will report our progress using this technique to realize mid-circuit measurement along with lossless spin-sensitive measurements. In addition, we will describe on-going work in which we perform two-qubit gates via a single-photon transition from the metastable to Rydberg state.