Bichromatic Tweezers for Qudit Quantum Computing in ${}^{87}$Sr

TL;DR

This paper proposes a bichromatic tweezer scheme to engineer magic trapping conditions for qudits in ${}^{87}$Sr, reducing light-shift dephasing and enabling improved coherence for quantum computing applications.

Contribution

It introduces a novel bichromatic trapping technique that suppresses differential light shifts across all magnetic sublevels of the ${}^{87}$Sr ${}^{3}P_2$ state, enhancing qudit coherence.

Findings

Suppression of differential light shifts using two wavelengths with opposite tensor light shifts.

Enabling scalar and tensor magic conditions for qudits in ${}^{87}$Sr.

Operation robustness at the tensor magic angle with linear polarization.

Abstract

Neutral atoms have become a competitive platform for quantum metrology, simulation, sensing, and computing. Current magic trapping techniques are insufficient to engineer magic trapping conditions for qudits encoded in hyperfine states with $J \neq 0$, compromising qudit coherence. In this paper we propose a scheme to engineer magic trapping conditions for qudits via bichromatic tweezers. We show it is possible to suppress differential light shifts across all magnetic sublevels of the $5s5p$ $\mathrm{^{3}P_2}$ state by using two carefully chosen wavelengths (with comparable tensor light shift magnitude and opposite sign) at an appropriate intensity ratio, thus suppressing light-shift induced dephasing, enabling scalar magic conditions between the ground state and $5s5p$ $\mathrm{^{3}P_2}$, and tensor magic conditions for qudits encoded within it. Furthermore, this technique enables robust operation at the tensor magic angle 54.7$^\circ$ with linear trap polarization via reduced sensitivity to uncertainty in experimental parameters. We expect this technique to enable new loading protocols, enhance cooling efficiency, and enhance nuclear spins' coherence times, thus facilitating qudit-based quantum computing in ${}^{87}$Sr in the $5s5p$ $\mathrm{^{3}P_2}$ manifold.