Solid-state quantum emitters are promising candidates for the realization of quantum networks, owing to their long-lived spin memories, high-fidelity local operations, and optical connectivity for long-range entanglement. However, due to differences in local environment, solid-state emitters typically feature a range of distinct transition frequencies, which makes it challenging to create optically mediated entanglement between arbitrary emitter pairs. We propose and demonstrate an efficient method for entangling emitters with optical transitions separated by many linewidths. In our approach, electro-optic modulators enable a single photon to herald a parity measurement on a pair of spin qubits. We experimentally demonstrate the protocol using two silicon-vacancy centers in a diamond nanophotonic cavity, with optical transitions separated by 7.4 GHz. Working with distinguishable emitters allows for individual qubit addressing and readout, enabling parallel control and entanglement of both colocated and spatially separated emitters, a key step toward scaling up quantum information processing systems.
Bibliographical noteFunding Information:
We thank Pavel Stroganov, Eric Bersin, Leigh Martin, and Neil Sinclair for discussions, Vikas Anant from PhotonSpot for providing SNSPDs, and Jim MacArthur for assistance with electronics. This work was supported by the NSF, Center for Ultracold Atoms, Award No. 1734011, Department of Defense Army Research Office Defense University Research Instrumentation Program, Air Force Office of Scientific Research Multidisciplinary University Research Initiatives, Office of Naval Research MURI, Army Research Lab, and a Vannevar Bush Faculty Fellowship. Devices were fabricated in the Harvard University Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Coordinated Infrastructure Network (NNCI), which is supported by the National Science Foundation under NSF Award No. 1541959. M. K. B. and D. S. L. acknowledge support from an National Defense Science and Engineering Fellowship. R. R. acknowledges support from the Alexander von Humboldt Foundation and the Cluster of Excellence “Advanced Imaging of Matter” of the Deutsche Forschungsgemeinschaft (DFG)—EXC 2056—Project No. 390715994. B. M. and E. N. K. acknowledge that this material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE1745303.
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