Abstract
Ensembles of solid-state optical emitters enable broadband quantum storage and transduction of photonic qubits, with applications in high-rate quantum networks for secure communications and interconnecting future quantum computers. To transfer quantum states using ensembles, rephasing techniques are used to mitigate fast decoherence resulting from inhomogeneous broadening, but these techniques generally limit the bandwidth, efficiency and active times of the quantum interface. Here, we use a dense ensemble of neodymium rare-earth ions strongly coupled to a nanophotonic resonator to demonstrate a significant cavity protection effect at the single-photon level—a technique to suppress ensemble decoherence due to inhomogeneous broadening. The protected Rabi oscillations between the cavity field and the atomic super-radiant state enable ultra-fast transfer of photonic frequency qubits to the ions (∼50 GHz bandwidth) followed by retrieval with 98.7% fidelity. With the prospect of coupling to other long-lived rare-earth spin states, this technique opens the possibilities for broadband, always-ready quantum memories and fast optical-to-microwave transducers.
Highlights
Ensembles of solid-state optical emitters enable broadband quantum storage and transduction of photonic qubits, with applications in high-rate quantum networks for secure communications and interconnecting future quantum computers
One major challenge towards broadband quantum interfaces based on solid-state emitters is that information stored in the collective excitation of the ensemble quickly decoheres due to inhomogeneous broadening
To restore the optical coherence, protocols based on spectral hole burning techniques like atomic frequency comb (AFC)[7,8] and controlled reversible inhomogeneous broadening[9] have been perfected
Summary
Ensembles of solid-state optical emitters enable broadband quantum storage and transduction of photonic qubits, with applications in high-rate quantum networks for secure communications and interconnecting future quantum computers. Ensembles of rare-earth ions doped in crystals exhibit outstanding quantum coherence properties and large inhomogeneous linewidths[1] that are suitable for quantum information transfer with broadband photons in high-speed optical quantum communication networks[2,3,4] They are used in state-of-the-art optical quantum memories with potential for microwave storage[5,6,7,8,9,10,11] and are promising candidates for opticalto-microwave quantum transduction[12,13]. To restore the optical coherence, protocols based on spectral hole burning techniques like atomic frequency comb (AFC)[7,8] and controlled reversible inhomogeneous broadening[9] have been perfected Effective, these protocols involve long (hundreds of milliseconds) and complex preparation procedures that generally limit the interface bandwidth. Exploiting the protected mapping of photonic qubits to atomic super-radiant excitations, we realize an efficient quantum light-matter interface with B50 GHz bandwidth that could find applications in future quantum networks
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
