Assembly and coherent control of a register of nuclear spin qubits

TL;DR

This paper presents an optical tweezer platform for assembling and controlling a 2D array of nuclear spin qubits in strontium-87, demonstrating long coherence times and individual qubit manipulation.

Contribution

It introduces a novel optical tweezer system for nuclear spin qubits with site-specific control and long coherence times, advancing quantum register development.

Findings

Negligible spin relaxation over 5 seconds

Estimated $T_2^* = 21 ext{ s}$, $T_2^{ ext{echo}} = 42 ext{ s}$

Successful individual and subset qubit manipulation

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 $T_1\gg5$ s. Furthermore, utilizing simultaneous manipulation of subsets of qubits, we demonstrate significant phase coherence over the entire register, estimating $T_2^\star = \left(21\pm7\right)$ s and measuring $T_2^\text{echo}=\left(42\pm6\right)$ s.