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arXiv 1106.4205cond-mat.mtrl-sci
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金属接触对LaAlO3/SrTiO3(001)界面二维电子气的调谐

Tuning the two-dimensional electron gas at the LaAlO3/SrTiO3(001) interface by metallic contacts

V. G. Ruiz López, R. Arras, W. E. Pickett, R. Pentcheva

摘要:

第一性原理计算表明,在LaAlO 3/SrTiO 3(001)上添加金属覆盖层可消除极性LaAlO 3薄膜内的电场,从而抑制未覆盖薄膜中观察到的厚度依赖的绝缘体-金属转变。与LaAlO 3厚度无关,表面和界面都是金属性的,在金属化过渡之后,相对于LaAlO 3/SrTiO 3(001)具有增强的界面载流子密度。此外,单层厚的金属Ti接触表现出有限的磁矩和薄SrTiO 3-衬底诱导自旋极化的2D电子气在n-型界面由于限制效应。给出了M/LaAlO_3/SrTiO_3(001)的能带排列图和M=Ti、Al和Pt的肖特基势垒。

英文摘要:

First principles calculations reveal that adding a metallic overlayer on LaAlO3/SrTiO3(001) eliminates the electric field within the polar LaAlO3 film and thus suppresses the thickness-dependent insulator-to-metal transition observed in uncovered films. Independent of the LaAlO3 thickness both the surface and the interface are metallic, with an enhanced interface carrier density relative to LaAlO3/SrTiO3(001) after the metallization transition. Moreover, a monolayer thick metallic Ti-contact exhibits a finite magnetic moment and for a thin SrTiO3-substrate induces a spin-polarized 2D electron gas at the n-type interface due to confinement effects. A diagram of band alignment in M/LaAlO3/SrTiO3(001) and Schottky barriers for M=Ti, Al, and Pt are provided.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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