quantum physics

Barium-based Rydberg atom quantum technologies with long Rydberg coherence

arXiv:2607.11282 · doi:10.1103/bbv3-d4ch

summary

The paper proposes a two‑photon excitation scheme for a specific barium Rydberg state that removes Doppler‑limited decoherence, providing long coherence times and strong dipole‑dipole interactions useful for neutral‑atom quantum computing and long‑lived Rydberg polaritons.

Abstract

The short Doppler-limited coherence time of the laser-excited Rydberg state, usually orders of magnitude shorter than the lifetime of the Rydberg state, hinders the Rydberg-mediated quantum technologies. Here, we show that a 649~nm~ $-$ ~658~nm two-photon excitation of the $6 s n g^{1} G_{4}$ Rydberg state from a long-lived d-orbital clock state of barium can be achieved with a two-photon wavevector that is tiny, which effectively removes the Doppler-limited decoherence. Moreover, the $6 s n g^{1} G_{4}$ Rydberg state has strong dipole-dipole interaction due to small FÃ¶rster defect with nearby Rydberg states and possesses long radiative lifetime. These can benefit quantum computing based on individually trapped neutral atoms, and can enable long-lived Rydberg polaritons in atomic media, which brings fresh opportunities in all-optical quantum information.

14 pages, 6 figures

Topics & keywords

#rydberg atoms #barium #quantum computing #neutral atom traps #coherence #dipole-dipole interactiontwo-photon excitationDoppler-free6sng ^1G_4 Rydberg stateFöster defectRydberg polaritonsradiative lifetime