2014/01/30 by Cécile Grèzes, Brian Julsgaard, Grezes, C. +29 · 3 citations
Materials Science · Physics and Astronomy · #Advanced Fiber Laser Technologies #Cold Atom Physics and Bose-Einstein Condensates #Diamond and Carbon-based Materials Research #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.1401.7939
openalex publication_date 2014/01/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A quantum memory at microwave frequencies, able to store the state of multiple superconducting qubits for long times, is a key element for quantum information processing. Electronic and nuclear spins are natural candidates for the storage medium as their coherence time can be well above one second. Benefiting from these long coherence times requires to apply the refocusing techniques used in magnetic resonance, a major challenge in the context of hybrid quantum circuits. Here we report the first implementation of such a scheme, using ensembles of nitrogen-vacancy (NV) centres in diamond coupled to a superconducting resonator, in a setup compatible with superconducting qubit technology. We implement the active reset of the NV spins into their ground state by optical pumping and their refocusing by Hahn echo sequences. This enables the storage of multiple microwave pulses at the picoWatt level and their retrieval after up to 35 μs, a three orders of magnitude improvement compared to previous experiments.