Hybridization in the exotic heavy fermions CeRhSn and CeIr3B2

Date

Feb 4, 2025

Time

3:00 PM - 4:00 PM

Speaker

Dr. Thomas Böhm

Affiliation

Los Almos National Laboratory / Los Alamos, NM, USA Postdoctoral Research Associate

Language

en

Main Topic

Materialien

Host

Rita Taubert

Description

Hybridization in the exotic heavy fermions CeRhSn and CeIr3B2 We investigated the optical conductivity σ_1 (ω,T) of quantum-critical CeRhSn and quasi one-dimensional CeIr3B2 heavy fermion systems. Pronounced spectral weight transfer occurs at high energies (~0.8 eV) and temperatures (~500 K) and indicates strong hybridization between conduction electrons and Ce 4f electrons. With decreasing temperature, a crossover from single-ion Kondo physics into an anisotropic coherent Kondo state with concomitant mass enhancement was detected. Our experimental results paved the way towards a refined theoretical analysis based on a combination of density functional theory and dynamic mean field theory. We found that local electronic correlations and mixed valency, as defined by the exact occupancy of the 4f state, play a crucial role to reproduce the observed spectroscopic signatures and photoemission results. Since descriptions of reduced dimensionality are by and large limited to T = 0 so far, our theory additionally presents an avenue towards studying the Kondo state in a wide temperature range, beyond the ground state properties.

Links

• Seminars at the IFW

Last modified: Feb 4, 2025, 7:37:49 AM