Fully Optical Modulation of the Two-Dimensional Electron Gas attheγ-Al2O3/SrTiO3Interface

作者：Niu, Wei; Fang, Yue-Wen; Liu, Ruxin; Wu, Zhenqi; Chen, Yongda; Gan, Yulin; Zhang, Xiaoqian; Zhu, Chunhui; Wang, Lixia; Xu, Yongbing; Pu, Yong^*; Chen, Yunzhong^*; Wang, Xuefeng^*

来源：Journal of Physical Chemistry Letters, 2022, 13(13): 2976-2985.

DOI：10.1021/acs.jpclett.2c00384

• TOTAL-ENERGY CALCULATIONS
• PERSISTENT PHOTOCONDUCTIVITY
• OXIDE
• INTERFACE
• HETEROSTRUCTURES
• MAGNETISM

Two-dimensional electron gas (2DEG) formed at the heterointerface betweentwo oxide insulators hosts plenty of emergent phenomena and provides new opportunities forelectronics and photoelectronics. However, despite being long sought after, on-demandproperties controlled through a fully optical illumination remain far from being explored.Herein, a giant tunability of the 2DEG at the interface of gamma-Al2O3/SrTiO3through a fullyoptical gating is discovered. Specifically, photon-generated carriers lead to a delicate tunabilityof the carrier density and the underlying electronic structure, which is accompanied by theremarkable Lifshitz transition. Moreover, the 2DEG can be optically tuned to possess amaximum Rashba spin-orbit coupling, particularly at the crossing region of the sub-bands withdifferent symmetries. First-principles calculations essentially well explain the optical modulationof gamma-Al2O3/SrTiO3. Our fully optical gating opens a new pathway for manipulating emergentproperties of the 2DEGs and is promising for on-demand photoelectric devices.

• 单位
  y; 南京邮电大学; 南京大学; 中国科学院