Terahertz conductivity of heavy-fermion systems from time-resolved spectroscopy
Abstract
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 CeCu6−xAux , 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. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000457268Publication status
publishedExternal links
Journal / series
Physical Review ResearchVolume
Pages / Article No.
Publisher
American Physical SocietySubject
Time-resolved THz Spectroscopy; HEAVY FERMIONS (CONDENSED MATTER PHYSICS)Organisational unit
03918 - Fiebig, Manfred / Fiebig, Manfred
Funding
178825 - Dynamical processes in systems with strong electronic correlations (SNF)
SEED-17 18-1 - Investigating ultrafast electron dynamics in topological crystalline insulators (ETHZ)
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