Nonlocality in superconducting microstructures - art. no. 064519

We discuss experimental evidence of nonlocality in superconducting nanostru ctures: the variation of the magnitude of the order parameter Delta (r) ind uces a response at a remote point r'. It is shown that reasonable agreement with experiment can be achieved by assuming nonlocal integral relation bet ween Delta (r) and Delta (r') with the kernel function K(r,r') proportional to (1/\r- r'\)exp(- \r- r'\/xi (Delta)). Numerically the correlation lengt h xi (Delta) is close ip to the effective Pippard's coherence length 0.18 x i (Pip)(0), while its dependence on the critical temperature T-c is differe nt than the conventional diverging behavior at the critical point T-->T-c.