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arXiv · 1810.07412

Fermi volume evolution and crystal field excitations in heavy-fermion compounds probed by time-domain terahertz spectroscopy

Shovon Pal·Christoph Wetli·Farzaneh Zamani·Oliver Stockert·Hilbert von Löhneysen·Manfred Fiebig·Johann Kroha
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Abstract

We measure the quasiparticle weight in the heavy-fermion compound CeCu$_{6-x}$Au$_{x}$ ($x=0,\ 0.1$) by time-resolved THz spectroscopy for temperatures from 2 up to 300\,K. This method distinguishes contributions from the heavy Kondo band and from the crystal-electric-field satellite bands by different THz response delay times. We find that the formation of heavy bands is controlled by an exponentially enhanced, high-energy Kondo scale once the crystal-electric-field states become thermally occupied. We corroborate these observations by temperature-dependent dynamical mean-field calculations for the multi-orbital Anderson lattice model and discuss consequences for quantum critical scenarios.

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Shovon Pal, Christoph Wetli, Farzaneh Zamani, Oliver Stockert, Hilbert von Löhneysen, Manfred Fiebig, Johann Kroha. 2019-03-07. Fermi volume evolution and crystal field excitations in heavy-fermion compounds probed by time-domain terahertz spectroscopy. https://doi.org/10.1103/physrevlett.122.096401

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