Decoherence of a single-ion qubit immersed in a spin-polarized atomic bath

TL;DR

This study investigates how a single trapped ion qubit's coherence is affected by immersion in a spin-polarized atomic bath, revealing detailed dynamics and unexpected decoherence mechanisms.

Contribution

It provides a first-principles understanding of decoherence in a single-ion qubit immersed in a spin-polarized environment, including identification of spin-nonconserving interactions.

Findings

Measured decoherence times T1 and T2.

Identified spin-exchange as a key decoherence mechanism.

Discovered unexpectedly strong spin-nonconserving coupling.

Abstract

We report on the immersion of a spin-qubit encoded in a single trapped ion into a spin-polarized neutral atom environment, which possesses both continuous (motional) and discrete (spin) degrees of freedom. The environment offers the possibility of a precise microscopic description, which allows us to understand dynamics and decoherence from first principles. We observe the spin dynamics of the qubit and measure the decoherence times (T1 and T2), which are determined by the spin-exchange interaction as well as by an unexpectedly strong spin-nonconserving coupling mechanism.