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arXiv · 2401.03934

Coherent excitation of a $\mu$Hz scale optical magnetic quadrupole transition

V. Klüsener·S. Pucher·D. Yankelev·J. Trautmann·F. Spriestersbach·D. Filin·S. G. Porsev·M. S. Safronova·I. Bloch·S. Blatt
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Abstract

We report on the coherent excitation of the ultranarrow $^{1}\mathrm{S}_0$-$^{3}\mathrm{P}_2$ magnetic quadrupole transition in $^{88}\mathrm{Sr}$. By confining atoms in a state insensitive optical lattice, we achieve excitation fractions of 97(1)% and observe linewidths as narrow as 58(1) Hz. With Ramsey spectroscopy, we find coherence times of 14(1) ms, which can be extended to 266(36) ms using a spin-echo sequence. We determine the linewidth of the M2 transition to 24(7) $\mu$Hz, confirming longstanding theoretical predictions. These results establish an additional clock transition in strontium and pave the way for applications of the metastable $^{3}\mathrm{P}_2$ state in quantum computing and quantum simulations.

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V. Klüsener, S. Pucher, D. Yankelev, J. Trautmann, F. Spriestersbach, D. Filin, S. G. Porsev, M. S. Safronova, I. Bloch, S. Blatt. 2024-01-08. Coherent excitation of a $\mu$Hz scale optical magnetic quadrupole transition. https://doi.org/10.1103/physrevlett.132.253201

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