Evidence of a hidden-order pseudogap state in URu2Si2 using ultrafast optical spectroscopy
Journal Article

Published: Tuesday, October 11, 2011
Citation: Physical Review B, Volume 84, Number 16, Pages 161101(R)
Link: http://prb.aps.org/abstract/PRB/v84/i16/e161101

Authors (8 total): M. Liu, R. Averitt, T. Durakiewicz, P. Tobash, E. Bauer, S. Trugman, A. J. Taylor, D. Yarotski

Abstract: Ultrafast optical spectroscopy was utilized to investigate carrier dynamics in the heavy-fermion compound URu2Si2 from 5 to 300 K. The amplitude and decay time of the photoinduced reflectivity increase in the vicinity of the coherence temperature T*∼57 K, consistent with the presence of a hybridization gap. At 25 K, a crossover regime manifests as a new feature in the carrier dynamics saturating below the hidden-order transition temperature of 17.5 K. This is indicative of a psuedogap region (17.5 K < T < 25 K) separating the normal Kondo-lattice state from the hidden-order phase. Rothwarf-Taylor modeling of the data yields values of ∼10 meV (5 meV) for the hybridization gap (hidden-order gap).