Pattern Formation by Electric-Field Quench in a Mott Crystal

The control of the Mott phase is intertwined with thespatial reorganizationof the electronic states. Out-of-equilibrium driving forces typicallylead to electronic patterns that are absent at equilibrium, whosenature is however often elusive. Here, we unveil a nanoscale patternformation in the Ca2RuO4 Mott insulator. Wedemonstrate how an applied electric field spatially reconstructs theinsulating phase that, uniquely after switching off the electric field,exhibits nanoscale stripe domains. The stripe pattern has regionswith inequivalent octahedral distortions that we directly observethrough high-resolution scanning transmission electron microscopy.The nanotexture depends on the orientation of the electric field;it is nonvolatile and rewritable. We theoretically simulate the chargeand orbital reconstruction induced by a quench dynamics of the appliedelectric field providing clear-cut mechanisms for the stripe phaseformation. Our results open the path for the design of nonvolatileelectronics based on voltage-controlled nanometric phases