No abstract

When a low flux of time-frequency-entangled photon pairs (EPP) illuminates a twophoton transition, the rate of two-photon absorption (TPA) can be enhanced considerably by the quantum nature of photon number correlations and frequency correlations. We present a quantum-theoretic derivation of entangled TPA (ETPA) and calculate an upper bound on the amount of quantum enhancement that is possible in such systems. The derived bounds indicate that in order to observe ETPA the experiments would need to operate at a combination of significantly higher rates of EPP illumination, molecular concentrations, and conventional TPA cross sections than are achieved in typical experiments.

No abstract

Entangled photons have been reported to enhance two-photon absorption by many orders of magnitude. Recent theoretical work predicts smaller increases for common molecular dyes. We present experimental results supporting this claim in Rhodamine 6G.

We present a theoretical proof that the “quantum enhancement” of two-photon absorption, thought to be a means to improve molecular spectroscopy and imaging, is tightly bounded by the physics of photonic entanglement and nonlinear response.