Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba, Japan.
Nat Commun. 2011 Oct 11;2:494. doi: 10.1038/ncomms1501.
The interface between LaAlO(3) and SrTiO(3) possesses a range of intriguing properties, notably a proposed connection between the surface state of the LaAlO(3) and the conductivity buried in the SrTiO(3). Here we study the effect of the surface adsorption of a variety of common laboratory solvents on the conductivity at the interface between LaAlO(3) and SrTiO(3). We show that the application of chemicals such as acetone, ethanol, and water can induce a large change in the conductivity, and, in particular, an insulator to metal transition around the critical LaAlO(3) thickness. This phenomenon is observed only for polar solvents. These data provide experimental evidence for a general polarization-facilitated electronic transfer mechanism.
LaAlO(3) 和 SrTiO(3) 的界面具有一系列有趣的性质，特别是 LaAlO(3) 的表面态和 SrTiO(3) 中埋入的电导率之间的拟议连接。在这里，我们研究了各种常见实验室溶剂在 LaAlO(3) 和 SrTiO(3) 界面的表面吸附对电导率的影响。我们表明，应用丙酮、乙醇和水等化学物质可以诱导电导率发生很大变化，特别是在 LaAlO(3) 厚度临界值附近发生绝缘体到金属的转变。这种现象仅在极性溶剂中观察到。这些数据为普遍的极化促进电子转移机制提供了实验证据。
