Upper critical field in heavy fermion systems

✍ Scribed by M. Tachiki; T. Koyama; S. Takahashi

• Publisher: Elsevier Science
• Year: 1985
• Weight: 202 KB
• Volume: 135
• Category: Article
• ISSN: 0378-4363
• DOI: 10.1016/0378-4363(85)90434-6

✦ Synopsis

For explaining the peculiar temperature dependence of the upper critical field He2 in UBe13 the following mechanism was considered: The He2 of UBe13 is extremely high at low temperatures and its intensity is comparable to the Kondo temperature in this compound. Therefore, the coherent state itself may be affected by the external field. The self-energy and vertex function of a quasielectron become field dependent. This field dependence causes the modification of the g-factor, the spin-orbit interaction and the pairing interaction of quasielectrons. Taking account of the modification and assuming singlet superconductivity, we calculated the He2 of the heavy fermion systems for various values of the parameters. The result shows that the calculated upper critical field is in good agreement with the experimental one in UBe13, if suitable values of the parameters are selected. The possibility of the reentrant superconductivity in the high field region is predicted.