We used Raman light scattering to study the current-stabilized nonequilibrium semimetallic and metallic phases in Ca2RuO4. By determining the local temperature through careful analysis of the Stokes and anti-Stokes intensities, we find that Joule heating can be completely avoided by supplying sufficient cooling power in a helium-flow cryostat, and that the current induces the semimetallic state without inducing any significant heating. We further investigate the current-induced semimetallic state as a function of temperature and current. We confirm the absence of long-range antiferromagnetic order and identify a substantial Fano broadening of several phonons, which suggests coupling to charge and orbital fluctuations. Our results demonstrate that the semimetallic state is a genuine effect of the applied electrical current and that the current-induced phases have characteristics distinct from the equilibrium ones.
@article{arxiv.1907.07905,
title = {Raman scattering from current-stabilized nonequilibrium phases in Ca$_2$RuO$_4$},
author = {K. Fürsich and J. Bertinshaw and P. Butler and M. Krautloher and M. Minola and B. Keimer},
journal= {arXiv preprint arXiv:1907.07905},
year = {2019}
}
Comments
accepted for publication as a Rapid Communication in Physical Review B