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Kondo coherence versus superradiance in terahertz radiation-driven heavy-fermion systems

Yang, Chia-Jung; Woerner, Michael; Stockert, Oliver; Löhneysen, Hilbert v. 1; Kroha, Johann; Fiebig, Manfred; Pal, Shovon
1 Institut für Nanotechnologie (INT), Karlsruher Institut für Technologie (KIT)

Abstract:

In strongly correlated systems such as heavy-fermion materials, the coherent superposition of localized and mobile spin states leads to the formation of Kondo resonant states, which on a dense, periodic array of Kondo ions develop lattice coherence. Characteristically, these quantum-coherent superposition states respond to a terahertz (THz) excitation by a delayed THz pulse on the scale of the material's Kondo energy scale and, hence, independent of the pump-light intensity. However, delayed response is also typical for superradiance in an ensemble of excited atoms. In this case, quantum coherence is established by the coupling to an external, electromagnetic mode and, hence, dependent on the pump-light intensity. In the present work, we investigate the physical origin of the delayed pulse, i.e., inherent, correlation-induced versus light-induced coherence, in the prototypical heavy-fermion compound CeCu_5.9Au_0.1. We study the delay, duration and amplitude of the THz pulse at various temperatures in dependence on the electric-field strength of the incident THz excitation, ranging from 0.3 to 15.2 kV/cm. We observe a robust delayed response at approximately 6 ps with an amplitude proportional to the amplitude of the incident THz wave. ... mehr


Volltext §
DOI: 10.5445/IR/1000171635
Veröffentlicht am 13.06.2024
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Nanotechnologie (INT)
Publikationstyp Forschungsbericht/Preprint
Publikationsjahr 2023
Sprache Englisch
Identifikator KITopen-ID: 1000171635
Umfang 6 S.
Vorab online veröffentlicht am 12.12.2023
Nachgewiesen in arXiv
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