相关论文: Superconducting Fluctuations in Granular Metals wi…
The magnetoresistance of a granular superconductor in a strong magnetic field is considered. It is assumed that this field destroys the superconducting gap in each grain, such that all interesting effects considered in the paper are due to…
The magnetoresistance of a granular superconductor in a strong magnetic field destroying the gap in each grain is considered. It is assumed that the tunneling between grains is sufficiently large such that all conventional effects of…
We suggest to use `fluctuation spectroscopy' as a method to detect granularity in a disordered metal close to a superconducting transition. We show that with lowering temperature $T$ the resistance $R(T)$ of a system of relatively large…
The electrical conductivity induced near the superconducting transition by thermal fluctuations was measured in different granular aluminum films. The seemingly anomalous behavior at high reduced temperatures and magnetic fields is…
We derive exact expressions for the fluctuation conductivity in two dimensional superconductors as a function of temperature and magnetic field in the whole fluctuation region above the upper critical field H_{c2}(T). Focusing on the…
Small superconducting grains are discussed in the frameworks of both the reduced BCS Hamiltonian and the Universal Hamiltonian. It is shown that fluctuations of electrons in levels far from the Fermi energy dominate superconducting…
We consider the behaviour of the fluctuating specific heat and conductivity in the vicinity of the upper critical field line for a two-band superconductor. Multiple-band effects are pronounced when the bands have very different coherence…
The effect of fluctuations on the transport and thermodynamic properties of two-dimensional superconductors in a magnetic field is studied at low temperature. The fluctuation conductivity is calculated in the framework of the perturbation…
Fluctuations are important near phase transitions, where they can be difficult to describe quantitatively. Superconductivity in mesoscopic rings is particularly intriguing because the critical temperature is an oscillatory function of…
We perform a detailed calculation of the various contributions to the fluctuation conductivity of a granular metal close to its superconducting transition. We find three distinct regions of power law behavior in reduced temperature,…
We study theoretically the contribution of fluctuating Cooper pairs to the persistent current in superconducting rings threaded by a magnetic flux. For sufficiently small rings, in which the coherence length $\xi$ exceeds the radius $R$,…
We extend previous theoretical studies of the contribution of fluctuating Cooper pairs to the persistent current in superconducting rings subjected to a magnetic field. For sufficiently small rings, in which the coherence length $\xi$…
A nano-scale metallic grain in which the single-particle dynamics are chaotic is described by the so-called universal Hamiltonian. This Hamiltonian includes a superconducting pairing term and a ferromagnetic exchange term that compete with…
The magnetization around the superconducting transition was measured in a Tl$_{0.5}$Pb$_{0.5}$Sr$_2$CaCu$_2$O$_7$ crystal affected by a considerable reduction ($\sim$55%) of its effective superconducting volume fraction but still with a…
We calculate fluctuation corrections to the longitudinal conductivity of disordered superconductors subject to an external magnetic field. We derive analytic expressions that are valid in the entire metallic part of the temperature-magnetic…
The first-order superconducting fluctuation corrections to the thermal conductivity of a granular metal are calculated. A suppression of thermal conductivity proportional to $T_c/(T-T_c)$ is observed in a region not too close to the…
We discuss electron transport in individual nanometer-scale metallic grains at dilution refrigerator temperatures. In the weak coupling regime, the grains exhibit Coulomb blockade and discrete energy levels. Electron-electron interactions…
We show results on the vortex core dissipation through current-voltage measurements under applied pressure and magnetic field in the superconducting phase of CeCoIn$_5$. We find that as soon as the system becomes superconducting, the vortex…
The paraconductivity, originating from critical superconducting order-parameter fluctuations in the vicinity of the critical temperature in a layered superconductor is calculated in the frame of the self-consistent Hartree approximation,…
Antiferromagnetic fluctuations are believed to be a promising glue to drive high-temperature superconductivity especially in cuprates. Here, we perform a close inspection of the superconducting mechanism from spin fluctuations in the…