Regensburg 2025 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 58: f-Electron Systems and Heavy Fermions

TT 58.6: Vortrag

Freitag, 21. März 2025, 12:45–13:00, H31

Coherent valence dynamics in UAl₃ — •Vinicius Estevo Silva Frehse¹, Hlynur Gretarsson², Eric Bauer³, Atsushi Hariki⁴, Filip Ronning³, and Marein Rahn¹ — ¹Center for Electronic Correlations and Magnetism, Augsburg, Germany — ²P01 High Resolution Dynamics Beamline, Hamburg, Germany — ³Institute for Materials Science, Los Alamos, USA — ⁴Department of Physics and Electronics, Osaka, Japan

The interaction between itinerant and localized electrons, as proposed by the Kondo model, enables the formation of heavy fermions, and unconventional superconductivity. In f-electron intermetallics with a large Kondo temperature, the emergence of lattice-coherent valence dynamics can be resolved by resonant inelastic x-ray scattering (RIXS). In the simple cubic, strongly valence fluctuating compound UAl₃, a coherent Fermi surface of Kondo quasiparticles emerges around T_coh∼ 200 K. We study the excitations of these quasiparticles using the newly available RIXS instrumentation for the tender x-ray range. The spectra indeed reveal dispersive trends of the 5f interband excitations at low temperatures, reminiscent of the isostructural 4f compound CePd₃[1]. [1] M.C.Rahn, et al., Nat. Comm. 13, 6129 (2022).

Keywords: Kondo lattice; RIXS; Actinides