Volume 32, Issue 12, December 2006
Index of content:
- SUPERCONDUCTIVITY, INCLUDING HIGH-TEMPERATURE SUPERCONDUCTIVITY
32(2006); http://dx.doi.org/10.1063/1.2400686View Description Hide Description
A numerical simulation of the stochastic resonance is carried out in the adiabatic approximation in overdamped systems based on superconducting loops closed by a weak link. The systems under consideration include a single-ring rf SQUID, two rings coupled by a common magnetic flux, and a ring closed by a 4-terminal Josephson junction. It is shown that coupling of single SQUID rings enhances the gain and the signal-to-noise ratio. These effects can be used to create new stochastic SQUIDantennas for measurements of harmonic and quasi-harmonic signals. The stochastic resonance in 4-terminal SQUIDS exists even at values of the dimensionless inductance.
Evolution of the pseudogap state in weakly praseodymium-doped single crystals with a specified topology of planar defects32(2006); http://dx.doi.org/10.1063/1.2400687View Description Hide Description
The basal-plane conductance is investigated in Y–Ba–Cu–O and single crystals having a system of unidirectional twin boundaries. It is shown that the partial substitution of Y by Pr leads to the formation of two superconducting phases with different critical temperatures. Praseodymium impurities are efficient scattering centers for normal and fluctuation carriers. In the case of weak doping (below the doping of Y–Ba–Cu–O single crystals with Pr brings about significant narrowing of the temperature interval in which the pseudogap state is realized in the plane.