Thermal effect in phase-periodic conductance of disordered mesoscopic N/S structures
Petrashov V.T., Shaikhaidarov R.Sh., Sosnin I.A.
We report measurements of the temperature dependence of the amplitude of phase-periodic conductance oscillations in disordered (diffusive) normal metal (Ag) structures attached to a superconducting (Pb) wire at two points. The amplitude of oscillations exceeds the value of e2//i by orders of magnitude and reaches its maximum at a temperature corresponding to the Thouless energy. The results support the recent theory [7], taking into account the characteristic energy dependence of the change in the diffusion coefficient of quasiparticles in a normal conductor due to Andreev reflections. The lineshape of the oscillations as a function of superconducting phase difference is found to be extremely sensitive to the quality of ΝIS interfaces and shows hystercsial behaviour m the interferometers with specially prepared clean interfaces. PACS: 74.50,+r