Ultrafast kinetic inductance samplers

The kinetic energy of electrons in conductors of all types is generally neglected when computing the intrinsic impedance of structures and devices. Except at very high frequencies this is a good approximation. In superconductors the kinetic energy contributes a strong kinetic inductance contribution to the impedance. We report use of the kinetic inductance to both generate and detect ultrafast voltage transients in superconducting device structures. Superconducting micro-bridge structures are fabricated from Tl2Ba2CaCu2O10 thin films which are then used to demonstrate ultrafast voltage sampling. A simple model for sampling is explained in terms of hot electron dynamics in the presence of a superconducting energy gap.