Hybridization gap formation in the Kondo insulator YbB${}_{12}$ observed using time-resolved photoemission spectroscopy

Abstract

A detailed low-energy electronic structure of a Kondo insulator YbB${}_{12}$ was revealed by a synergetic combination of ultrahigh-resolution laser photoemission spectroscopy (PES) and time-resolved PES. The former confirmed a 25-meV pseudogap corresponding to the Kondo temperature of this material, and more importantly, it revealed that a 15-meV gap and a Kondo-peak feature developed below a crossover temperature $T^{\ast }\sim 110$ K. In harmony with this, the latter discovered a very long recombination time exceeding 100 ps below $\sim$$T^{\ast }$. This is a clear manifestation of photoexcited carriers due to the bottleneck in the recovery dynamics, which is interpreted as a developing hybridization gap of a hard gap.

6 pages, 4 figures, revised version accepted for publication in PRB Rapid Communications

References in corpus (6)

• Surface electronic structure of the topological Kondo insulator candidate correlated electron system SmB6
• Correlated Topological Insulators with Mixed Valence
• Hybridization, Inter-Ion Correlation, and Surface States in the Kondo Insulator SmB6
• Gigantic surface life-time of an intrinsic topological insulator revealed via time-resolved (pump-probe) ARPES
• Time-resolved photoemission apparatus achieving sub-20-meV energy resolution and high stability
• Angle-resolved Photoemission Spectroscopy Study on the Surface States of the Correlated Topological Insulator YbB6

Cited by in corpus (8)

• Quantum Oscillations of Electrical Resistivity in an Insulator
• Surface Kondo Effect and Non-Trivial Metallic State of the Kondo Insulator YbB12
• Unconventional thermal metallic state of charge-neutral fermions in an insulator
• Unusual high-field metal in a Kondo insulator
• Hall anomaly, Quantum Oscillations and Possible Lifshitz Transitions in Kondo Insulator YbB${}_{12}$: Evidence for Unconventional Charge Transport
• Cyclotron resonance in Kondo insulator
• Topological surface states in the Kondo insulator YbB${}_{12}$ revealed via planar tunneling spectroscopy
• Robust hybridization gap in a Kondo Insulator YbB${}_{12}$ probed by femtosecond optical spectroscopy