Southwest Quantum Information and Technology

Broadband nanophotonic quantum interface with a cavity-protected rare-earth ensemble

Presenting Author: Tian Zhong, Faraon Group (IQIM, Caltech)
Contributing Author(s): Jonathan Kindem, Jake Rochman, Andrei Faraon

Ensembles of solid-state optical emitters are at the core of hybrid quantum interfaces between spins, optical, and microwave photons. To transfer information at quantum level, decoherence resulting from ensemble inhomogeneous broadening is currently suppressed using optical spin rephrasing techniques based on spectral hole burning, which require long preparation steps and reduce the interface bandwidth. We demonstrate that a solid-state ensemble of neodymium rare-earth ions strongly coupled to a photonic crystal resonator exhibits polaritons with strongly suppressed decoherence via the cavity protection phenomenon. Without using preparation steps, frequency qubits are stored and retrieved from the two polaritons with 98.7% fidelity and 50GHz bandwidth. The polaritons are supperadiant modes with emission rates >10^6 greater than uncoupled rare-earth ions, which enable ultra-fast (20 ps) control of the neodymium ensemble. Combined with long-lived spin-wave storage in rare-earth crystals, these results enable always-ready, on-demand, high-bandwidth quantum memories.

(Session 13 : Saturday from 3:45 pm - 4:15 pm )