Metals near quantum critical points have been predicted to display universal out-of equilibrium behavior in the steady current-carrying state. We have studied the non-linear conductivity of high-quality CaRuO3 thin films with residual resistivity ratio up to 57 using micro-second short, high-field current pulses at low temperatures. Even for the shortest pulses of 5μs, Joule heating persists, making it impossible to observe a possible universal non-linearity. Much shorter pulses are needed for the investigation of universal non-linear conductivity.
@article{arxiv.1402.6845,
title = {Nonlinear conductivity in CaRuO3 thin films measured by short current pulses},
author = {Sven Esser and Sebastian Esser and Christian Stingl and Philipp Gegenwart},
journal= {arXiv preprint arXiv:1402.6845},
year = {2014}
}