Emergence of a metallic metastable phase induced by electrical current in Ca2RuO4

A comprehensive study of the behavior of the Mott insulator ${\mathrm{Ca}}_{2}{\mathrm{RuO}}_{4}$ under electrical current drive is performed by combining two experimental probes: the macroscopic electrical transport and the microscopic x-ray diffraction. The resistivity, $\ensuremath{\rho}$, versus electric current density, $J$, and temperature, $T,\ensuremath{\rho}(J,T)$, resistivity map is drawn. In particular, the metastable state, induced between the insulating and the metallic thermodynamic states by current biasing ${\mathrm{Ca}}_{2}{\mathrm{RuO}}_{4}$ single crystals, is investigated. Such an analysis, combined with the study of the resulting ${\mathrm{RuO}}_{6}$ octahedra energy le…