Fine-Structure Qubit Encoded in Metastable Strontium Trapped in an Optical Lattice

TL;DR

This paper demonstrates coherent control of a fine-structure qubit in metastable strontium atoms trapped in an optical lattice, achieving high coherence and fast single-qubit operations, advancing quantum information processing and simulation.

Contribution

It introduces a novel method for encoding and coherently controlling a fine-structure qubit in neutral strontium atoms with long coherence times and rapid operations.

Findings

Over 60 Rabi oscillations observed

Coherence times of tens of milliseconds achieved

Single-qubit rotations performed on microsecond timescale

Abstract

We demonstrate coherent control of the fine-structure qubit in neutral strontium atoms. This qubit is encoded in the metastable $^3\mathrm{P}_2$ and $^3\mathrm{P}_0$ states, coupled by a Raman transition. Using a magnetic quadrupole transition, we demonstrate coherent state-initialization of this THz qubit. We show Rabi oscillations with more than 60 coherent cycles and single-qubit rotations on the $\mu$s scale. With spin-echo, we demonstrate coherence times of tens of ms. Our results pave the way for fast quantum information processors and highly tunable quantum simulators with two-electron atoms.