Observation of Transient Response of Nb Superconducting Thin Film to a Single-Heavy-Ion Impact

Abstract

Transient response of a 2500 Å thick superconducting Nb film to the impact of a single 129Xe50+ ion of total energy 3.2 GeV, transferring about 2.4 keV/Å of electronic excitation energy, was observed by means of a superconductor-insulator-superconductor tunnel junction attached to the film some distance away from the impact point. The response had rise time of less than 150 ps (resolution limit of the electronic detection system) and decay time varying from 2 to 1.3 ns as function of temperature. Main experimental features, if not finer details, are in good agreement with Rothwarf and Taylor theory of nonequilibrium processes in superconductors.

Ion beam induced surface and interface engineering

“…It is possible with fs pulse techniques to supply energy to the electronic carriers in a time shorter than the characteristic time for energy exchange with the lattice. Such irradiation would thus initially creates an extremely hot carrier gas in a cold lattice for a heavy ion irradiation [270]. In such laser irradiation the increment of the lattice temperature is due to the electron-atom interaction after the thermalization of the energy deposited on the electron system.…”

An Algorithmic Complexity Interpretation of Lin's Third Law of Information Theory

“…The selection mechanism of particular bits of the input sequence x by the solid (similar to the way f is defined for a selection rule in §4) is due to the solid's complex response to the presence of a sequence of particles hitting it. For instance, a solid's dielectric constants or material nonhomogeneity cause a nonlinear response to particle bombardment, e.g., photoconductive solid materials bombarded by photon particles [17] and superconductive thin films hit by ions [11] exhibit transient responses. This is analogous to the impulse response of a non-perfect filter in communication systems.…”