Nonadiabatic transitions between adiabatic surfaces: phase diffusion in superconducting atomic point contacts - Condensed Matter > Mesoscale and Nanoscale PhysicsReport as inadecuate




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Abstract: Motivated by experiments with current biased superconducting atomic pointcontacts the general problem of nonadiabatic transitions between adiabaticsurfaces in presence of strong dissipation is studied. For a single channeldevice the supercurrent is determined by the diffusive motion of thesuperconducting phase difference on two Andreev levels. These surfaces areuncoupled only in the adiabatic limit of low to moderate transmissions, whilefor high transmissions curve crossings are important. Starting from a generalmaster equation of the full density matrix an approximate time evolutionequation for the populations on the adiabatic surfaces in the overdamped limitis derived from which the relevant observables can be obtained. Specificresults for the case of atomic point contacts are in agreement withexperimental observations that cannot be explained by conventional theory.



Author: Hans Fritz, Joachim Ankerhold

Source: https://arxiv.org/







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