Schwinger boson approach to the Kondo lattice model
Jiangfan Wang1*, Yung-Yeh Chang1, Chung-Yu Mou2, Stefan Kirchner3, Silke Paschen4, Chung-Hou Chung1
1Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan
2Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
3Department of Physics, Zhejiang University, Hangzhou, China
4Institute of Solid State Physics, Vienna University of Technology, Vienna, Austria
* Presenter:Jiangfan Wang,
The microscopic mechanism of the heavy-fermion systems close to anti-ferromagnetic quantum critical point constitutes an outstanding open problem in correlated electron systems. To address this issue, we employ a distinct route from the dynamical mean-field theory by solving the 2D Kondo-Heisenberg model via a dynamical large-N multichannel Schwinger boson approach. We identify the quantum critical point separating the anti-ferromagnetic long-ranged ordered and the heavy Kondo-screened Fermi-liquid phases. Various thermodynamical observables near criticality show non-Fermi liquid behaviors and agree qualitatively well with the experiments seen in CeCu6-xAux and YbRh2Si2.

Keywords: Heavy fermion, Non-Fermi liquid, Quantum critical point, Schwinger boson