Vortex-based single-photon response in nanostructured superconducting detectors

In nanostructured superconducting films interaction of magnetic vortices with radiation quanta provides an additional mechanism of radiation detection. Below the Kosterlitz–Thouless topological transition, absorbed photon may cause vibration of vortex–antivortex paires and/or pinned vortices or weakening the superconductivity that facilitates thermal depinning of single vortices, dissociation of pairs or vortex entry. We present experimental indications of vortex-based detection mechanism in superconducting nanowire single-photon detectors.