| authors: | Heon-Jung Kim, Jae-Hyuk Choi, Hyeonjin Doh, Eun-Mi Choi, Sung-Ik Lee National Creative Research Initiative Center for Superconductivity and Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea |
The effect of pressure on the superconductivity and magnetism in Ho(1-x)DyxNi2B2C is studied both theoretically and experimentally. When P = 0 GPa, based on a phenomenological model of multiband superconductivity in an antiferromagnetic state, the breakdown of de Gennes scaling in this compound when the superconducting transition temperature is less than the Neel temperature (Tc < TN) can be explained. In this formalism, we describe the magnetic fluctuations and orders phenomenologically and explain the anomalous behavior of the upper critical field. The doping dependence of Tc which shows the reentrance behavior is well explained by this theory. The validity of this model is further confirmed by transport experiments under pressure for x = 0.1 and x = 0.4. In the case of the x = 0.1 (Tc < TN), increasing pressure decreases Tc, but pressure has no influence on the Tc of the x = 0.4 sample (Tc > TN). The pressure dependence of the upper critical field also supports the phenomenological theory of multiband superconductivity in an antiferromagnetic state.
Keyword: antiferromagnetism, superconductivity PACS 74.20.De, 74.62.Fj, 75.50.Ee