Photon-Instanton Collider Implemented by a Superconducting Circuit

Instantons, spacetime-localized quantum field tunneling events, arc ubiquitous in correlated condensed matter and high-energy systems. However, their direct observation through collisions with conventional particles has not been considered possible. We show how recent advances in circuit quantum electrodynamics, specifically, the realization of galvanic coupling of a transmon qubit to a high-impedance transmission line, allows the observation of inelastic collisions of single microwave photons with instantons (phase slips). We develop a formalism for calculating the photon-instanton cross section, which should be useful in other quantum field theoretical contexts. In particular, we show that the inelastic scattering probability can significantly exceed the effect of conventional Josephson quartic anharmonicity and mach order-unity values.

Automated summary

Recent advances in circuit quantum electrodynamics have enabled the observation of inelastic collisions between single microwave photons and instantons, offering insights for research in other quantum field theoretical contexts. The study also indicates that the inelastic scattering probability can significantly exceed the impact of conventional Josephson quartic anharmonicity and mach order-unity values.