Robust hybridization gap in a Kondo Insulator YbB probed by femtosecond optical spectroscopy
arXiv:2103.03284 · doi:10.1103/PhysRevB.103.115134
Abstract
In heavy fermions the relaxation dynamics of photoexcited carriers has been found to be governed by the low energy indirect gap, E, resulting from hybridization between localized moments and conduction band electrons. Here, carrier relaxation dynamics in a prototype Kondo insulator YbB is studied over large range of temperatures and over three orders of magnitude. We utilize the intrinsic non-linearity of dynamics to quantitatively determine microscopic parameters, such as electron-hole recombination rate. The extracted value reveals that hybridization is accompanied by a strong charge transfer from localized 4f-levels. The results imply the presence of a hybridization gap up to temperatures of the order of E/k K, which is extremely robust against electronic excitation. Finally, below 20 K the data reveal changes in the low energy electronic structure, attributed to short-range antiferromagnetic correlations between the localized levels.
References in corpus (21)
- Quasiparticle relaxation dynamics in superconductors with different gap structures: theory and experiments on YBa_{2}Cu_{3}O_{7-δ}
- Hybridization, Inter-Ion Correlation, and Surface States in the Kondo Insulator SmB6
- Kinetics of a superconductor excited with a femtosecond optical pulse
- Pair-breaking and superconducting state recovery dynamics in MgB2
- Quantum Oscillations of Electrical Resistivity in an Insulator
- Energy-gap dynamics of superconducting NbN thin films studied by time-resolved terahertz spectroscopy
- Skyrme insulators: insulators at the brink of superconductivity
- Quasiparticle relaxation dynamics in heavy fermion compounds
- Temperature-dependent Fermi surface evolution in heavy fermion CeIrIn5
- Evidence for short-range antiferromagnetic fluctuations in Kondo-insulating YbB12
- Surface Kondo Effect and Non-Trivial Metallic State of the Kondo Insulator YbB12
- Photoexcited electron dynamics in Kondo insulators and heavy fermions
- Non-equilibrium phenomena in superconductors probed by femtosecond time-domain spectroscopy
- Indirect and direct energy gaps in the Kondo semiconductor YbB12
- Hybridization dynamics in CeCoIn5 revealed by ultrafast optical spectroscopy
- Bulk Fermi surface of charge-neutral excitations in SmB6 or not: a heat-transport study
- Quantum oscillations in strongly correlated topological Kondo insulators
- Coupling Between An Optical Phonon and the Kondo Effect
- Hybridization gap formation in the Kondo insulator YbB observed using time-resolved photoemission spectroscopy
- Ultrafast terahertz spectroscopy study of Kondo insulating thin film SmB: evidence for an emergent surface state
- Melting the Superconducting State in the Electron Doped Cuprate PrCeCuO with Intense near-infrared and Terahertz Pulses