High-pressure induced modifications in the hybridization gap of the intermediate-valence compound SmB6

作者：Nishiyama K; Mito T^*; Pristas G; Koyama T; Ueda K; Kohara T; Gabani S; Flachbart K; Fukazawa H; Kohori Y; Takeshita N; Shitsevalova N; Ikeda H

来源：Physical Review B, 2016, 93(12): 121111.

DOI：10.1103/PhysRevB.93.121111

We have carried out the measurements of high-pressure B-11-nuclear magnetic resonance on the intermediate-valence compound SmB6 to investigate the effects of pressure on Sm 4f states and the quasiparticle band. From the measurements of spin-lattice relaxation time, just below the critical pressure Pc of nonmagnetic-magnetic phase transition, we find that quasiparticle bandwidth clearly decreases with pressure, while the insulating gap is almost constant or slightly increases. The latter is consistent with the result of a band-structure calculation. These pressure induced modifications in the band structure indicate the enhancement of the density of states of the quasiparticles when approaching P-c. The pressure dependence of the Sm 4f states and the origin of the insulating gap are well explained in terms of exchange interactions between conduction and 4f electrons.

• 出版日期2016-3-28