Critical Fluctuations in Superconductors and the Magnetic Field Penetration Depth

Critical fluctuations in superconductors and the magnetic field penetration depth.

The superconducting transition is studied within the one-loop RG in fixed dimension D = 3 and at the critical point. A tricritical behavior is found and, for κ > κc, an attractive charged fixed point, distinct from that of a neutral superfluid. The critical exponents of the continuous transition are evaluated and it is shown that the anomalous dimension of the gauge-field equals unity. This imp...

Magnetic Penetration Depth Measurements in Cuprate Superconductors

We examine recent results on measurements of the magnetic penetration depth in cuprate superconductors, with particular emphasis on our results obtained with the microstrip and parallel-plate resonator techniques. The results show that the magnetic penetration depth temperature dependence in YBa2Cu307-a is not consistent with a simple scaled weak-coupled BCS temperature dependence. We present t...

Magnetic field dependence of the penetration depth of d-wave superconductors with strong isolated impurities

A d-wave superconductor with isolated strong non-magnetic impurities should exhibit an upturn in the penetration depth at low temperatures [1]. Here we calculate how an external magnetic field supresses this effect.

Campbell penetration depth in Fe-based superconductors

.......................................................................................... v CHAPTER 1: INTRODUCTION.................................................................. 1 CHAPTER 2: LABUSCH PARAMETER AND CAMPBELL PENETRATION DEPTH.......................................................... 6 Introduction...................................................................................

Magnetic Nerve Stimulation: Field Focality and Depth of Penetration