Nanophotonics (Nov 2021)

Topological protection of continuous frequency entangled biphoton states

  • Jiang Zhen,
  • Ding Yizhou,
  • Xi Chaoxiang,
  • He Guangqiang,
  • Jiang Chun

DOI
https://doi.org/10.1515/nanoph-2021-0371
Journal volume & issue
Vol. 10, no. 16
pp. 4019 – 4026

Abstract

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Topological quantum optics that manipulates the topological protection of quantum states has attracted special interests in recent years. Here we demonstrate valley photonic crystals implementing topologically protected transport of the continuous frequency entangled biphoton states. We numerically simulate the nonlinear four-wave mixing interaction of topological valley kink states propagating along the interface between two valley photonic crystals. We theoretically clarify that the signal and idler photons generated from the four-wave mixing interaction are continuous frequency entangled. The numerical simulation results imply that the entangled biphoton states are robust against the sharp bends and scattering, giving clear evidence of topological protection of entangled photon pairs. Our proposal paves a concrete way to perform topological protection of entangled quantum states operating at telecommunication wavelengths.

Keywords