Realization of a fast triple-magic all-optical qutrit in strontium-88

TL;DR

This paper demonstrates a novel triple-magic optical trapping condition in strontium-88, enabling a high-coherence, all-optical qutrit with potential applications in quantum metrology and quantum information processing.

Contribution

It introduces the first realization of a triple-magic trapping condition in strontium-88, allowing high-fidelity control and long coherence times of a three-level atomic system.

Findings

Achieved triple-magic trapping conditions at a specific magic angle.

Demonstrated fast optical control of a strontium-88 qutrit.

Measured atom-atom coherence times up to 715 ms.

Abstract

The optical clock states of alkaline earth and alkaline earth-like atoms are the fundament of state-of-the-art optical atomic clocks. An important prerequisite for the operation of optical clocks are magic trapping conditions, where electronic and motional dynamics decouple. Here, we identify and experimentally demonstrate simultaneous magic trapping for two clock transitions in strontium-88, realizing so-called triple-magic conditions at a specially chosen magic angle. Under these conditions, we operate an all-optical qutrit comprising the ground state $^1S_0$, and the two metastable clock states $^3P_0$ and $^3P_2$. We demonstrate fast optical control in an atom array using two- and three-photon couplings to realize high-fidelity manipulation between all qutrit states. At the magic angle, we probe the coherence achievable in magic-angle-tuned traps and find atom-atom coherence times between the metastable states as long as 715(30) ms. Our work opens several new directions, including qutrit-based quantum metrology on optical transitions and high-fidelity and high-coherence manipulation on the strontium-88 fine-structure qubit.