2009/05/02 by H. Bary-Soroker, Hamutal Bary-Soroker, O. Entin‐Wohlman +3
Physics and Astronomy · #Condensed matter physics #Cooper pair #Copper #Energy (signal processing) #Impurity #Materials science #Mesoscopic physics #Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum mechanics #Superconductivity #Theoretical and Computational Physics #Transition temperature #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.80.024509
published as Phys. Rev. B 80, 024509 (2009)
arxiv created 2009/05/02 · openalex publication_date 2009/07/16 · arxiv updated 2015/05/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We consider the contribution of superconducting fluctuations in the mesoscopic persistent current (PC) of an ensemble of normal metallic rings, made of a superconducting material whose low bare transition temperature Tc0 is much smaller than the Thouless energy Ec. The effect of pair breaking is introduced via the example of magnetic impurities. We find that over a rather broad range of pair-breaking strength \ensuremathℏ/\ensuremathτs, such that Tc0\ensuremath\lesssim\ensuremathℏ/\ensuremathτs\ensuremath\lesssimEc, the superconducting transition temperature is normalized down to minute values or zero while the PC is hardly affected. This may provide an explanation for the magnitude of the average PCs in copper and gold as well as a way to determine their Tc0's. The dependence of the current and the dominant superconducting fluctuations on Ec\ensuremathτs and on the ratio between Ec and the temperature is analyzed. The measured PCs in copper (gold) correspond to Tc0 of a few (a fraction of) mK.