Terahertz conductivity of heavy-fermion systems from time-resolved spectroscopy

Autor: Chia-Jung Yang, Shovon Pal, Farzaneh Zamani, Kristin Kliemt, Cornelius Krellner, Oliver Stockert, Hilbert v. Löhneysen, Johann Kroha, Manfred Fiebig
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Physical Review Research, Vol 2, Iss 3, p 033296 (2020)
Druh dokumentu: article
ISSN: 2643-1564
DOI: 10.1103/PhysRevResearch.2.033296
Popis: The Drude model describes the free-electron conduction in simple metals, governed by the freedom that the mobile electrons have within the material. In strongly correlated systems, however, a significant deviation of the optical conductivity from the simple metallic Drude behavior is observed. Here, we investigate the optical conductivity of the heavy-fermion system CeCu_{6−x}Au_{x}, using time-resolved, phase-sensitive terahertz spectroscopy. The terahertz electric field creates two types of excitations in heavy-fermion materials: First, the intraband excitations that leave the heavy quasiparticles intact. Second, the resonant interband transitions between the heavy and light parts of the hybridized conduction band that break the Kondo singlet. We find that the Kondo-singlet-breaking interband transitions do not create a Drude peak, while the Kondo-retaining intraband excitations yield the expected Drude response. This makes it possible to separate these two fundamentally different correlated contributions to the optical conductivity.
Databáze: Directory of Open Access Journals