标题： 高磁场和压力下CeRh2Si2中的费米面不稳定性 显示英文标题

标题： Fermi surface instabilities in CeRh2Si2 at high magnetic field and pressure

摘要： 我们展示了在低温下，CeRh2Si2反铁磁体在压力和高磁场下的热电功率（TEP）研究。在磁场下，在反铁磁相中观察到热电功率S(H)的显著量子振荡。当进入极化顺磁（PPM）状态时，这些振荡突然消失，指出费米面（FS）的重要重构。在压力下，S/T在临界压力Pc附近的低温下强烈增加，此时AF序被抑制，暗示了由自旋和价态涨落驱动的费米面变化和低能激发之间的相互作用。在Hc以上的PPM状态中的TEP信号与在Pc以上的顺磁状态（PM）中的TEP信号之间的差异可以由不同的费米面来解释。在P=0应力下的能带结构计算表明，在AF相中费米能级（EF）的4f贡献较弱，而在PM区域中则是主要贡献。类比于之前对CeRu2Si2的研究，在CeRh2Si2的PPM相中，EF处的4f贡献将下降。 显示英文摘要

摘要： We present thermoelectric power (TEP) studies under pressure and high magnetic field in the antiferromagnet CeRh2Si2 at low temperature. Under magnetic field, large quantum oscillations are observed in the TEP, S(H), in the antiferromagnetic phase. They suddenly disappear when entering in the polarized paramagnetic (PPM) state at Hc pointing out an important reconstruction of the Fermi surface (FS). Under pressure, S/T increases strongly of at low temperature near the critical pressure Pc, where the AF order is suppressed, implying the interplay of a FS change and low energy excitations driven by spin and valence fluctuations. The difference between the TEP signal in the PPM state above Hc and in the paramagnetic state (PM) above Pc can be explained by different FS. Band structure calculations at P = 0 stress that in the AF phase the 4f contribution at the Fermi level (EF) is weak while it is the main contribution in the PM domain. By analogy to previous work on CeRu2Si2, in the PPM phase of CeRh2Si2 the 4f contribution at EF will drop.