  In this work we have studied the effect of light and electric field on the
electrical properties of La0.7Sr0.3MnO3 (LSMO) film at 300 K. Taking advantage
of it's charge, spin, orbital and lattice degrees of freedom, we have
successfully shown that light and electric field together can be used to tune
the resistance states of the manganite system. Using applied gate voltage (Vg)
and light we were able to obtain a change in resistance of about +/-7.5%.
Furthermore, incorporating an ultra thin interfacial LaTiO3 (LTO) layer
provides valuable insight on the origin of the photoinduced effect. The
observed photoinduced effect is attributed to photoexcited down spin eg
electrons, interfacial charge injection and manipulation of orbital occupancy
depending on the gate voltage and wavelength of light.
