Title, author, abstract

title

UPPER CRITICAL FIELD OF MULTILAYERS WITH DIFFERENT COHERENCE LENGTHS

authors

Teruo Matsushita and Yoshinori Nakayama
Department of Computer Science and Electronics, Kyushu Institute of Technology,
680--4 Kawazu, Iizuka, 820 JAPAN

abstract

The upper critical field of multilayers with different coherence lengths under a normal magnetic field is theoretically investigated using the Ginzburg-Landau theory with a simple assumption on the spatial variation in the order parameter. The case of Nb-Ti with artificially introduced Nb as pinning centers is treated as an example. It is found that the upper critical field is seriously degraded by the proximity effect. The present result agrees well with the result of microscopic theory of Takahashi and Tachiki. The method of the Ginzburg-Landau theory with an approximate expression of the order parameter seems to be useful for a theoretical estimation on the pinning property which is difficult to treat with the microscopic theory.

Original paper appears in

9th International Symposium on Superconductivity
October 21--25, 1996
Sapporo, Hokkaido, Japan

• paper(gzip PS file, 47Kbyte)