Volume 34, Issue 6, June 2008
Index of content:
- SUPERCONDUCTIVITY, INCLUDING HIGH-TEMPERATURE SUPERCONDUCTIVITY
Analysis of the pseudogap-related structure in the tunnel spectra of superconducting revealed by break-junction technique34(2008); http://dx.doi.org/10.1063/1.2920074View Description Hide Description
The tunnel conductance for break junctions made of as-grown single-crystal samples with is measured, and clear-cut dip–hump structures are found in the range of bias voltage . A theory of tunneling in symmetric junctions between inhomogeneous charge-density-wave(CDW)superconductors, considered in the framework of the -pairing model, is developed. It is shown that CDWs are responsible for the appearance of the dip–hump structure in the tunnel current–voltage characteristics, and a proper description of the experimental results is obtained.
34(2008); http://dx.doi.org/10.1063/1.2920076View Description Hide Description
We analyze the influence of noise on magnetic properties of a superconducting loop which contains three Josephson junctions. This circuit is a classical analog of a persistent current (flux) qubit. A loop supercurrent induced by external magnetic field in the presence of thermal fluctuations is calculated. To connect with experiment, we calculate the impedance of a low-frequency tank circuit which is inductively coupled with the loop of interest. We compare the results with the results obtained in the quantum mode — when the three junction loop exhibits quantum tunneling of the magnetic flux. We demonstrate that the tank–loop impedance in the classical and quantum modes have different temperature dependence and can be easily distinguished experimentally.