Electric field control of the photoinduced resistance increase in La0.7Sr0.3MnO3/LaTiO3/SrTiO3 heterostructure

In this work we study the effect of light and electric field on the electrical properties of a La0.7Sr0.3MnO3 film at 300 K Taking advantage of its charge, spin, orbital, and lattice degrees of freedom, we successfully show that light and electric field together can be used to tune the resistance states of the manganite system. Using applied gate voltage V-g and light, we are able to obtain a change in resistance of about +/- 7.5%. Furthermore, incorporating an ultrathin interfacial LaTiO3 layer provides valuable insight into the origin of the photoinduced effect. The observed photoinduced effect is attributed to photoexcited down-spin e(g down arrow) electrons, interfacial charge injection, and manipulation of orbital occupancy depending on the gate voltage and wavelength of light.