Extended Rydberg Lifetimes in a Cryogenic Atom Array

TL;DR

This paper demonstrates significantly extended Rydberg state lifetimes in a cryogenic environment, enabling improved coherence for neutral-atom quantum computing.

Contribution

The authors achieve over three times longer Rydberg lifetimes by operating in a 4K cryogenic environment, advancing the potential for high-fidelity quantum gates.

Findings

Rydberg lifetimes up to 406 microseconds in cryogenic conditions

Reduced dephasing due to small differential polarizability

Enhanced prospects for high-fidelity neutral-atom quantum gates

Abstract

We report on the realization of a $^{133}$Cs optical tweezer array in a cryogenic blackbody radiation (BBR) environment. By enclosing the array within a 4K radiation shield, we measure long Rydberg lifetimes, up to $406 (36)\,\mu$s for the $55 P_{3/2}$ Rydberg state, a factor of 3.3(3) longer than the room-temperature value. We employ single-photon coupling for coherent manipulation of the ground-Rydberg qubit. We measure a small differential dynamic polarizability of the transition, beneficial for reducing dephasing due to light intensity fluctuations. Our results pave the path for advancing neutral-atom two-qubit gate fidelities as their error budgets become increasingly dominated by $T_1$ relaxation of the ground-Rydberg qubit.