Spin-optomechanical cavity interfaces by deep subwavelength phonon-photon confinement

Journal Article · Mon Jul 14 00:00:00 EDT 2025 · npj Quantum Information

DOI:https://doi.org/10.1038/s41534-025-00999-x· OSTI ID:2583713

Raniwala, Hamza ^[1]; Anand, Pratyush ^[1]; Krastanov, Stefan ^[2]; Eichenfield, Matt ^[3]; Trusheim, Matthew ^[4]; Englund, Dirk R. ^[1]

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1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
2. Univ. of Massachusetts, Amherst, MA (United States)
3. Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Univ. of Arizona, Tucson, AZ (United States)
4. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Army Research Laboratory, Adelphi, MD (United States)

A central goal of quantum information science is transferring qubits between space, time, and modality. Spin-based systems in solids are promising quantum memories, but high-fidelity transfer of their quantum states to telecom optical fields remains challenging. Here, we introduce a phonon-mediated interface between spins in a diamond nanobeam optomechanical crystal and telecom optical fields by a simultaneous deep-subwavelength confinement of optical and acoustic fields with mode volumes $$V_{\textrm{mech}}$$$$/Λ^3_\textrm{p} ~ 10^{-5}$$ and $$V_{\textrm{opt}}$$$$/λ^3 ~ 10^{−3}$$, respectively. This confinement boosts the spin-mechanical coupling rate of Group-IV silicon vacancy (SiV⁻) centers by an order of magnitude to ~ 32 MHz while retaining high acousto-optical couplings. The optical cavity couples to the spin irrespective of the emitter’s native excited states, avoiding spectral diffusion. Using Quantum Monte Carlo simulations, we estimate heralded entanglement fidelities exceeding 0.96 between two such interfaces. We anticipate broad utility beyond diamond emitter-telecom systems to most solid-state quantum memories.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: National Science Foundation (NSF); US Air Force Office of Scientific Research (AFOSR); USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF)
• Grant/Contract Number: NA0003525
• OSTI ID: 2583713
• Journal Information: npj Quantum Information, Journal Name: npj Quantum Information Journal Issue: 1 Vol. 11; ISSN 2056-6387
• Publisher: Nature Partner Journals
• Country of Publication: United States
• Language: English