Antiferromagnetism and superconductivity in heavy-fermion compounds

[[abstract]]Antiferromagnetism is self-consistently built into the Periodic Anderson model at the mean-field level. Unlike the Heisenberg model, the Neel temperature is found to decrease with increasing staggered field due to the presence of the Kondo effect (consistent with the pressure and doping experiments). Only a finite range of the staggered field is able to stabilize the magnetism (consistent with the upper bound found experimentally for the pressure), and the ordered moment can vary sensitively with the field (consistent with the observation of small substitutions of Pt by Pd in UPt3). Assuming the existence of a pairing mechanism, not necessarily of the electron-phonon type, we find that the superconducting transition temperature Tc is always enhanced by the antiferromagnetism. There is an optimum Tc for a fixed pairing potential. For large J values Tc drops with increasing J (in line with the suppression of Tc by pressure)[[fileno]]2010106010048[[department]]物理學