Zhang Fan, Lv Peng, Zhang Yiteng, Huang Shujin, Wong Chi-Man, Yau Hei-Man, Chen Xinxin, Wen Zheng, Jiang Xiaoning, Zeng Changgan, Hong Jiawang, Dai Ji-Yan
Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, 999077 Kowloon, Hong Kong.
Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina, 27606, USA.
Phys Rev Lett. 2019 Jun 28;122(25):257601. doi: 10.1103/PhysRevLett.122.257601.
Thin film flexoelectricity is attracting more attention because of its enhanced effect and potential application in electronic devices. Here we find that a mechanical bending induced flexoelectricity significantly modulates the electrical transport properties of the interfacial two-dimensional electron gas (2DEG) at the LaAlO_{3}/SrTiO_{3} (LAO/STO) heterostructure. Under variant bending states, both the carrier density and mobility of the 2DEG are changed according to the flexoelectric polarization direction, showing an electric field effect modulation. By measuring the flexoelectric response of LAO, it is found that the effective flexoelectricity in the LAO thin film is enhanced by 3 orders compared to its bulk. These results broaden the horizon of study on the flexoelectricity effect in the hetero-oxide interface and more research on the oxide interfacial flexoelectricity may be stimulated.
薄膜挠曲电效应因其增强的效应以及在电子器件中的潜在应用而受到越来越多的关注。在此我们发现，机械弯曲诱导的挠曲电效应显著调制了LaAlO₃/SrTiO₃（LAO/STO）异质结构界面二维电子气（2DEG）的电输运性质。在不同的弯曲状态下，2DEG的载流子密度和迁移率均根据挠曲电极化方向发生变化，呈现出电场效应调制。通过测量LAO的挠曲电响应，发现LAO薄膜中的有效挠曲电效应相比于其体材料增强了3个数量级。这些结果拓宽了对异质氧化物界面挠曲电效应的研究视野，并可能激发更多关于氧化物界面挠曲电效应的研究。
