Département de Physique de la Matière Condensée, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Genève 4, Switzerland.
Phys Rev Lett. 2010 Mar 26;104(12):126803. doi: 10.1103/PhysRevLett.104.126803.
The quasi-two-dimensional electron gas found at the LaAlO{3}/SrTiO{3} interface offers exciting new functionalities, such as tunable superconductivity, and has been proposed as a new nanoelectronics fabrication platform. Here we lay out a new example of an electronic property arising from the interfacial breaking of inversion symmetry, namely, a large Rashba spin-orbit interaction, whose magnitude can be modulated by the application of an external electric field. By means of magnetotransport experiments we explore the evolution of the spin-orbit coupling across the phase diagram of the system. We uncover a steep rise in Rashba interaction occurring around the doping level where a quantum critical point separates the insulating and superconducting ground states of the system.
在 LaAlO3/SrTiO3 界面处发现的准二维电子气提供了令人兴奋的新功能,例如可调谐超导性,并被提议作为新的纳米电子制造平台。在这里,我们提出了一个新的例子,即界面打破反转对称性会产生电子特性,即大的 Rashba 自旋轨道相互作用,其大小可以通过施加外部电场来调节。通过磁输运实验,我们研究了系统相图中自旋轨道耦合的演变。我们发现 Rashba 相互作用在掺杂水平附近急剧上升,在该掺杂水平处,量子临界点将系统的绝缘和超导基态分开。