Variational Monte Carlo study of magnetic states in the periodic Anderson model

Kubo, Katsunori

Journal of Physics; Conference Series, 592(1), p.012039_1 - 012039_6, 2015/03

https://doi.org/10.1088/1742-6596/592/1/012039

Anisotropic magnetic fluctuations in YbRhSi

Kambe, Shinsaku; Sakai, Hironori; Tokunaga, Yo; Lapertot, G.*; Matsuda, Tatsuma*; Knebel, G.*; Flouquet, J.*; Walstedt, R. E.*

Journal of Physics; Conference Series, 592(1), p.012085_1 - 012085_5, 2015/03

https://doi.org/10.1088/1742-6596/592/1/012085

Recently there is renewed interest in quantum critical phase transitions (QCPT) at K in metallic strongly-correlated electron systems. From early experimental results, the QCPT in the Kondo-lattice compound YbRhSi is not a case of the ordinary spin density wave (SDW) instability observed in Ce-based Kondo-lattices, but a candidate for a novel locally critical case In new observations reported here, we find that coexisting, static Fermi liquid (FL) and non-Fermi liquid (NFL) states are a key feature of the QCPT in YbRhSi. Such a pair of states has remained hidden in Ce compounds, owing presumably to short lifetimes for the two states. A new scaling law for the occupation ratio of the two states is derived, and could be widely applicable to Kondo-lattice systems.

Synchrotron X-ray spectroscopy study on the valence state and magnetization in -YbAlFeB () at low temperatures and high magnetic fields

Terashima, Taku*; Matsuda, Yasuhiro*; Kuga, Kentaro*; Suzuki, Shintaro*; Matsumoto, Yosuke*; Nakatsuji, Satoru*; Kondo, Akihiro*; Kindo, Koichi*; Kawamura, Naomi*; Mizumaki, Masaichiro*; et al.

Journal of Physics; Conference Series, 592(1), p.012020_1 - 012020_6, 2015/03

https://doi.org/10.1088/1742-6596/592/1/012020

Valence fluctuation phenomena in rare-earth intermetallic compounds have attracted attention because the quantum criticality of the valence transition has been proposed theoretically. Recently, it was found that -YbAlB shows quantum criticality without tuning and has a strong mixed-valence state. In this study, we measured the magnetization curve and X-ray magnetoabsorption in -YbAlFeB (), which is a locally isostructural polymorph of -YbAlB. The magnetization and X-ray experiments were performed in fields up to 55 and 40 T, respectively. A small increase in the Yb valence was observed at fields where the magnetization curve exhibited a change in slope.

High-resolution X-ray diffraction experiment on the octupole ordered phase in CeLaB

Inami, Toshiya; Michimura, Shinji*; Matsumura, Takeshi*; Hayashi, Yuya*; Sera, Masafumi*; Iga, Fumitoshi*

no journal, , 

We have carried out a high-resolution X-ray diffraction experiment at low temperatures and in magnetic fields on CeLaB that exhibits antiferrooctupole (AFO) order below =1.4K. Ferroquadrupole moments that accompany the AFO order and a resultant rhombohedral deformation of the cubic lattice were theoretically predicted and experimetanlly supported. However, the sign and magnitude of the rhombohedral deformation have not yet been determined. We observe the splitting of Bragg peaks below , which is consistent with a rhombohedral deformation of 4 elongated along the [111] axis. The response of rhombohedral domains to magnetic fields also well agrees with theoretical calculations. A particular outcome of this experiment is that the magnitude of the induced quadrupole moments is precisely evaluated from the obtained shear strain.