Universal gate operations on nuclear spin qubits in an optical tweezer array of $^{171}$Yb atoms

TL;DR

This paper demonstrates universal quantum gate operations on nuclear spin qubits in $^{171}$Yb atoms within optical tweezer arrays, achieving high fidelity and long coherence times, advancing neutral atom quantum computing.

Contribution

It introduces techniques for cooling, trapping, and manipulating nuclear spin qubits in $^{171}$Yb atoms, including two-qubit gates via Rydberg blockade and coherent control methods.

Findings

Qubit lifetime of approximately 20 seconds.

Single-qubit gate fidelity of 0.99959.

Successful implementation of two-qubit entangling gates.

Abstract

Neutral atom arrays are a rapidly developing platform for quantum science. In this work, we demonstrate a universal set of quantum gate operations on a new type of neutral atom qubit: a nuclear spin in an alkaline earth-like atom (AEA), $^{171}$Yb. We present techniques for cooling, trapping and imaging using a newly discovered magic trapping wavelength at $\lambda = 486.78$ nm. We implement qubit initialization, readout, and single-qubit gates, and observe long qubit lifetimes, $T_1 \approx 20$ s and $T^*_2 = 1.24(5)$ s, and a single-qubit operation fidelity $\mathcal{F}_{1Q} = 0.99959(6)$. We also demonstrate two-qubit entangling gates using the Rydberg blockade, as well as coherent control of these gate operations using light shifts on the Yb$^+$ ion core transition at 369 nm. These results are a significant step towards highly coherent quantum gates in AEA tweezer arrays.