Fig. 1: Exploring fermionic quantum criticality by time-resolved THz reflectivity.
From: Critical slowing down near a magnetic quantum phase transition with fermionic breakdown
a, Schematic phase diagram of YbRh2Si2 with characteristic energy scales as defined in the text. AFM, antiferromagnetic phase. b, Reflected THz signal from the YbRh2Si2 sample (red) and from a Pt mirror reference (black). The time traces are normalized by the maximum field amplitude at t = 0 ps. The delayed, purely Kondo-related ‘echo’ pulse is visible in the interval between 1.3 and 2.6 ps, where it distinctly differs from the Pt reference signal. c, Subtracted signal of the delayed pulse in YbRh2Si2 at B⊥ = 70 mT for various temperatures.
