Assembly and coherent control of a register of nuclear spin qubits

Abstract

We introduce an optical tweezer platform for assembling and individually manipulating a two-dimensional register of nuclear spin qubits. Each nuclear spin qubit is encoded in the ground ${}^1{S}_0$ manifold of ${}^{87}$Sr and is individually manipulated by site-selective addressing beams. We observe that spin relaxation is negligible after 5 seconds, indicating that $T_1\gg 5$ s. Furthermore, utilizing simultaneous manipulation of subsets of qubits, we demonstrate significant phase coherence over the entire register, estimating $T_2^{\star }=\left(21\pm 7\right)$ s and measuring $T_2^{\text{echo}}=\left(42\pm 6\right)$ s.