Non-linear quantum critical dynamics and fluctuation-dissipation ratios far from equilibrium

Abstract

Non-thermal correlations of strongly correlated electron systems and the farfrom-equilibrium properties of phases of condensed matter have become a topical research area. Here, an overview of the non-linear dynamics found near continuous zero-temperature phase transitions within the context of effective temperatures is presented. In particular, we focus on models of critical Kondo destruction. Such a quantum critical state, where Kondo screening is destroyed in a critical fashion, is realized in a number of rare earth intermetallics. This raises the possibility of experimentally testing for the existence of fluctuationdissipation relations far from equilibrium in terms of effective temperatures near quantum criticality. Finally, we present an analysis of a non-interacting, critical reference system, the pseudogap resonant level model, in terms of effective temperatures and contrast these results with those obtained near interacting quantum critical points.

Mixed-Order Symmetry-Breaking Quantum Phase Transition Far from Equilibrium

“…Here ΓL,R = 0.01. and criticality, which signal the absence of intrinsic energy scales and make the system particularly susceptible to any non-equilibrium drive [29][30][31][32][33][34][35]. Phase-transitions under non-equilibrium conditions [7,[36][37][38][39][40][41][42][43][44] were shown to allow intrinsic non-equilibrium universal properties, not seen at equilibrium. Nevertheless, a systematic approach describing CCSS is not available and exact solutions therefore must serve as a guiding principle.…”