Electric-field switching of orbital order in layered manganites

Abstract

We have investigated the electric-field effect on the orbital-ordered state of eg electrons for layered manganites Nd1−xSr1+xMnO4 near the phase boundary between antiferro d3x2−r2/d3y2−r2 and ferro d3x2−r2 orbital-ordered phases. By means of a polarization microscope in crossed-Nicol configuration, we can distinguish these two orbital-ordered phases, and observed the electric-field switching between the two phases. This indicates that the electric-field can affect the directional order of orbital, and the system with the two competitive orbital-ordered states bears the orbital analog of the liquid-crystal functionality.