2022/07/07(Thu)
10:30 -12:00
五樓第一會議室 5F, 1st Meeting Room
視訊演講 Video Seminar [ Meeting Link / ID: 2516 688 4019 / Password: 123456 ]
Title
A mechanism for the strange metal phase in rare-earth intermetallic compounds
Speaker
仲崇厚教授 (國立陽明交通大學電子物理學系) Prof. Chung-Hou Chung (Department of Electrophysics, National Yang Ming Chiao Tung University)Abstract
A major mystery in strongly interacting quantum systems is the microscopic origin of the “strange metal” phenomenology, with unconventional metallic behavior that defies Landau’s Fermi liquid framework for ordinary metals. This state is found across a wide range of quantum materials, notably in rare-earth intermetallic compounds at finite temperatures (T) near a magnetic quantum phase transition, and shows a quasilinear-in-temperature resistivity and a logarithmic-in-temperature specific heat coefficient. Recently, an even more enigmatic behavior pointing toward a stable strange metal ground state was observed in CePd1−xNixAl, a geometrically frustrated Kondo lattice compound. Here, we propose a mechanism for such phenomena driven by the interplay of the gapless fermionic short-ranged antiferromagnetic spin correlations (spinons) and critical bosonic charge (holons) fluctuations near a Kondo breakdown quantum phase transition [1]. Within a dynamical large-N approach to the Kondo–Heisenberg lattice model, the strange metal phase is realized in transport and thermodynamical quantities. It is manifested as a fluctuating Kondo-scattering–stabilized critical (gapless) fermionic spin-liquid metal. It shows ω/T scaling in dynamical electron scattering rate, a signature of quantum criticality. Our results offer a qualitative understanding of the CePd1−xNixAl compound [2] and suggest a possibility of realizing the quantum critical strange metal phase in correlated electron systems in general.
Abstract
Language
演講語言 (Language): in English