25 research outputs found
Josephson effect in d-wave superconductor junctions in a lattice model
Josephson current between two d-wave superconductors is calculated by using a
lattice model. Here we consider two types of junctions, , the parallel
junction and the mirror-type junction. The maximum Josephson current
shows a wide variety of temperature () dependence depending on the
misorientation angles and the types of junctions. When the misorientation
angles are not zero, the Josephson current shows the low-temperature anomaly
because of a zero energy state (ZES) at the interfaces. In the case of
mirror-type junctions, has a non monotonic temperature dependence. These
results are consistent with the previous results based on the quasiclassical
theory. [Y. Tanaka and S. Kashiwaya: Phys. Rev. B \textbf{56} (1997) 892.] On
the other hand, we find that the ZES disappears in several junctions because of
the Freidel oscillations of the wave function, which is peculiar to the lattice
model. In such junctions, the temperature dependence of is close to the
Ambegaokar-Baratoff relation.Comment: 17 pages, 10 figures, using jpsj2.cls and oversite.st
Plantation-Seeding Forest Plantations – the New Method for Regeneration of Coniferous Forests at Large Clearings on Burned Lands
The new method of restoration of coniferous stands on large felling areas on burnt lands that lack seed trees is discussed. It involves limited planting of big grafted seedlings of quality wood, that have a high level of seed production, with the purpose of the subsequent natural sowing on these territories. Results of two-year-old research on approbation of the method on cuttings on large felling areas on burnt lands in conditions of the mid-Ob' river pine forests are stated. A good viability of «seed cultures» is noted. There is damage of the grafting pines by elk. Therefore there is a problem of protecting plantations against elk. For preservation of a high level of genetic variability of pine stands it is desirable to use in «seed cultures» the best trees from local plantings
Current states in superconducting films: Numerical results
We present numerical solutions of Aslamazov–Lempitskiy (AL) equations for distributions of the transport
current density in thin superconducting films in the absence of external magnetic field, in both the Meissner and
the vortex states. These solutions describe smooth transition between the regimes of a wide film and a narrow
channel and enable us to find critical currents and current-voltage characteristics within a wide range of the film
width and temperature. The normalized critical currents and the electric field were found to be universal functions
of the relation between the film width and the magnetic field penetration depth. We calculate the fitting
constants of the AL theory and propose approximating formulas for the current density distributions and critical
currents