Entangled-photon interactions with plasmas and quantum plasma sensing

Entangled photons are a quantum state of light that has no classical counterpart and can only be described quantum optically. Entangled photons have been used in quantum teleportation, secure quantum communication, precise quantum metrology and ghost imaging. In conjunction with the latest single-photon detectors and correlated photon-detection schemes, non-local photon correlations open doors to quantum-enhanced plasma sensing possibilities. In addition to entangled photon generation through parametric down-conversion, relativistic plasmas (such as plasma mirrors) may Doppler-shift entangled photons to shorter wavelengths to produce higher energy entangled photon pairs. Here we summarize several fundamental interactions between entangled photons and plasmas, e.g. phase shift, reflection, and coherent scattering, which motivate new quantum plasma sensing schemes such as intensity interferometers [1].