Nonlinear Response abobve the Superconducting Transition Point. I

First-order superconducting transition near a ferromagnetic quantum critical point.

We address the issue of how triplet superconductivity emerges in an electronic system near a ferromagnetic quantum critical point (FQCP). Previous studies found that the superconducting transition is of second order, and T(c) is strongly reduced near the FQCP due to pair-breaking effects from thermal spin fluctuations. In contrast, we demonstrate that near the FQCP, the system avoids pair-break...

Casimir energy and the superconducting phase transition

We study the influence of Casimir energy on the critical field of a superconducting film, and we show that by this means it might be possible to directly measure, for the first time, the variation of Casimir energy that accompanies the superconducting transition. It is shown that this novel approach may also help clarifying the long-standing controversy on the contribution of TE zero modes to t...

Sensing with Superconducting Point Contacts

Superconducting point contacts have been used for measuring magnetic polarizations, identifying magnetic impurities, electronic structures, and even the vibrational modes of small molecules. Due to intrinsically small energy scale in the subgap structures of the supercurrent determined by the size of the superconducting energy gap, superconductors provide ultrahigh sensitivities for high resolu...

The superconducting transition width and illumination wavelength dependence of the response of MgO substrate YBCO transition edge bolometers

Dependence of the phase and magnitude of the response of MgO substrate YBa2Cu3O7 d (YBCO) transition edge bolometers to the near infrared radiation on the superconducting transition width is presented in this work. The bolometers were made of YBCO thin films of 200 nm thickness that were grown on single crystal MgO (100) substrates by DC inverted cylindrical magnetron sputtering. We have measur...

Andreev-reflection and Point-contact Spectroscopy of Superconducting Rare Earth Transition Metal Borocarbides