Department of Materials Science, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ, United Kingdom.
Phys Rev Lett. 2009 Oct 16;103(16):166802. doi: 10.1103/PhysRevLett.103.166802.
The thickness and origin of the free charge layer which forms at the LaAlO_{3}/SrTiO_{3} interface is still uncertain. By inserting Mn dopants at different distances from the interface we can locate the position of carriers within the SrTiO3 surface layers. We show that the majority of the carriers in fully-oxygenated samples are confined within 1 unit cell of the interface. This confirms the "polar-catastrophe" mechanism proposed for this system but the low mobility of these carriers demonstrates the need for improved materials for applications and a more complete understanding of the role of the minority of higher mobility carriers identified.
在 LaAlO_{3}/SrTiO_{3} 界面形成的自由电荷层的厚度和起源仍不确定。通过在不同距离处插入 Mn 掺杂剂，我们可以定位 SrTiO3 表面层内的载流子位置。我们表明，在完全氧化的样品中，大多数载流子被限制在界面的 1 个单元内。这证实了该体系中提出的“极性灾难”机制，但这些载流子的低迁移率表明需要改进材料以应用，并更全面地了解少数高迁移率载流子的作用。
