Inelastic scattering of a photon by a quantum phase-slip

Understand

Spontaneous decay of a single photon is a notoriously inefficient process in nature irrespective of the frequency range.

• We report that a quantum phase-slip fluctuation in high-impedance superconducting waveguides can split a single incident microwave photon into a large number of lower-energy photons with a near unit probability.
• The underlying inelastic photon-photon interaction has no analogs in non-linear optics.
• Instead, the measured decay rates are explained without adjustable parameters in the framework of a new model of a quantum impurity in a Luttinger liquid.