Flexoelectric Modulation on the Two-Dimensional Electron Gas at (110) LaAlO3/SrTiO3 Interfaces

Flexoelectricity has been proven to be an effective way in tailoring a material's properties. Here, we report the flexoelectricity-induced transport modulation to the two-dimensional electron gas at the (110) LaAlO3/SrTiO3 systems. Under different strain gradients induced by mechanical bending, the interfacial resistance changes according to the flexoelectric field directions. By measuring the electrical transport properties of the interface under variant strain states, we demonstrate that the modulation effect is affected by the oxygen partial pressure during film deposition. The electrical field effect model can thoroughly explain the observations. These findings further clarify the physical picture of flexoelectric effects in oxide heterostructures.