Spin-Photon Interfaces

Photons are the ideal carriers of quantum information and will play a major role in future quantum networks. However, the contribution of photons to networking has been limited because photons do not interact with each other and suffer from losses over distance. These issues can be mitigated by establishing interfaces between photons and optically-active spins. Such interfaces can generate effective photon-photon interactions and be used to build quantum repeaters for the mitigation of photon losses. We use nanofabrication tools such as E-beam lithography, dry and wet etching to couple optically-active spins to photonic structure, thereby establishing efficient spin-photon interfaces.


In the figure: an SEM image of a nanofabricated “Bullseye” photonic cavity, whose coupling to a quantum dot leads to an optical transparency of 80% useful for quantum networking.

Promising research directions:

  • Optimization of spin-photon interfaces:
    • 1. Inverse design of photonic structures (e.g., using machine learning) for the optimization of desired figures of merit.
    • 2. Surface treatment of semiconductors for the minimization of charge noise in spin-photon interfaces.
  • Coupling of photonic structures to new optically-active spins toward quantum networking.
  • Demonstration of deterministic spin-photon and photon-photon entanglement for the generation of photonic graph states and quantum repeaters.
  • Deterministic nanofabrication of photonic structures around chosen emitters.
  • Automated characterization of photonic structures (using pattern recognition / machine learning).

Related publications:

  • S. Dutta, Y. Zhao, U. Saha, D. Farfurnik, E. A. Goldschmidt, and E. Waks. An Atomic Frequency Comb Memory in Rare-Earth Doped Thin-Film Lithium Niobate. ACS Photonics 10, 1104-1109 (2023).
  • H. Singh*, D. Farfurnik*, Z. Luo, A. S. Bracker, S. G. Carter, and E. Waks. Optical Transparency Induced by a Largely Purcell-Enhanced Quantum Dot in a Polarization-Degenerate Cavity. Nano Lett. 22, 7959-7964 (2022). *- Equal Contributors.
  • N. Alfasi, S. Masis, R. Winik, D. Farfurnik, O. Shtempluck, N. Bar-Gill, and E. Buks. Exploring the nonlinear regime of light-matter interaction using electronic spins in diamond. Phys. Rev. A 97, 063808 (2018).