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Robust hybridization gap in a Kondo Insulator YbB${}_{12}$ probed by femtosecond optical spectroscopy
- Source :
- Phys. Rev. B 113, 115134 (2021)
- Publication Year :
- 2021
-
Abstract
- In heavy fermions the relaxation dynamics of photoexcited carriers has been found to be governed by the low energy indirect gap, E$_{g}$, resulting from hybridization between localized moments and conduction band electrons. Here, carrier relaxation dynamics in a prototype Kondo insulator YbB${}_{12}$ 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$_{g}$/k$_{B}\approx200$ 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.
Details
- Database :
- arXiv
- Journal :
- Phys. Rev. B 113, 115134 (2021)
- Publication Type :
- Report
- Accession number :
- edsarx.2103.03284
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1103/PhysRevB.103.115134