Enhanced multiphoton ionization driven by quantum light

We present a framework for multiphoton ionization driven by arbitrary quantum states of light. Our simulations predict that cross sections can be enhanced by more than two orders of magnitude with momentum-entangled photons produced by modern nanoscale quantum light sources. The enhancement is tied to the broad angular spectrum of such sources, and is severely underestimated by conventional approaches using the paraxial approximation. Reasonable estimates of the resonant two-photon ionization cross section in sodium atoms indicate that these effects should be observable with current technology.