Strange metal state in paramagnetic heavy-fermion Kondo lattice: Dynamical large-N fermionic multi-channel approach

Jiangfan Wang¹, Yung-Yeh Chang^1,2*, Chung-Hou Chung^1,2

¹Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan
²Physics Division, National Center for Theoretical Sciences, Hsinchu, Taiwan

* Presenter:Yung-Yeh Chang, email:cdshjtr@gmail.com

The mechanism of strange metal state with unconventional charge transport near magnetic phase transitions has become an outstanding open problem in correlated electron systems. Recently, an exotic quantum critical strange metal phase was observed in paramagnetic frustrated heavy-fermion materials near Kondo breakdown. We establish a controlled theoretical framework to this issue via a dynamical large-N fermionic multichannel approach to the two-dimensional Kondo-Heisenberg lattice model, where Kondo breakdown transition separates a heavy-Fermi liquid from fermionic spin-liquid state. With Kondo fluctuations being fully considered, we find a distinct strange metal behavior with quasi-linear-in-temperature scattering rate associated with Kondo breakdown. When particle-hole symmetry is present, signatures of a critical spin-liquid strange metal phase as the temperature approaches zero are revealed with frequency-to-temperature (ω/T) scaling extended to a wide range. We attribute these features to the interplay of critical bosonic charge (Kondo) fluctuations and gapless fermionic spinons. The implications of our results for the experiments are discussed. Please refer to the preprint arXiv:2005.03427 for details.

Keywords: Strange metal, Heavy-fermion materials, Kondo lattice, Quantum criticality