Exotic Superconductivity in the Coexistent Phase of Antiferromagnetism and Superconductivity in CeCu_2(Si_<0.98>Ge_<0.02>)_2 : A Cu-NQR Study under Hydrostatic Pressure(Condensed Matter : Electronic Structure, Electrical, Magnetic and Optical Properties)

概要

論文の詳細を見る
We report a pressure (P) effect on CeCu_2(Si_<0.98>Ge_<0.02>)_2 where an antiferromagnetic (AFM) order at T_N 〜 0.75K coexists with superconductivity below T_c 〜 0.4K. At pressures exceeding P = 0.19GPa,the AFM order is suppressed, which demonstrates that the sudden emergence of AFM order due to the Ge doping is ascribed to the intrinsic lattice expansion. The exotic superconductivity at P = 0GPa is found to evolve into a typical heavy-fermion one with a line-node gap above P = 0.91 GPa. We highlight that the anomalous enhancement in nuclear spin-lattice relaxation rate 1/T_1 that follows a T_1T = const, behavior well below T_c at P = 0GPa is characterized by the persistence of low-lying magnetic excitations, which may be inherent to the coexistent state of antiferromagnetism and superconductivity.
社団法人日本物理学会の論文
2004-01-15