Hideaki Kasai

Yoshimori-Kasai Model Phase Diagram and Naniwa Series for Quantum Dynamics

We present the phase diagram of heavy fermions system (HFS) and muon adsorption calculations on Pd (111) surface. HFS undergoes phase transitions from Fermi liquid (FL) to non-Fermi liquid (NFL). Furthermore, antiferromagnetic (AF), spin-density wave (SDW)and superconductivity can be realized by changing electron densities and temperature. It is shown that at upper Hubbard band filling, HFS changes phase from antiferromagnetic to superconducting at low temperatures. Furthermore, in an attempt to elucidate muon dynamics on surfaces and subsurfaces, we show thatmuon exhibits tunneling effects independent of surface vibrations from quantum dynamical calculations. The results shown herein may have important implications on future ultra-slow muon experiments.

Density Functional Study of Spin Polarization on a Carbon Material with a Hexagonal Structure Induced by Iron Atoms

We investigate the spin polarization of a non magnetic material, e.g., a carbon material made from ten C atoms forming a hexagonal structure with total spin S = 0, induced by a ferromagnetic material, e.g., two Fe atoms with a total spin S = 4. Based on the density functional theory, we calculate the total spin density of the system. Our preliminary results show that the total spin for the ten C atoms changes from S = 0 to S = 4, while the total spin of the two Fe atoms changes from S = 4 to S =0. These results seem to indicate that there is a promising possibility to induce spin polarization on a carbon material by Fe atoms.