Quantum many-body interactions in digital oxide superlattices
Quantum many-body interactions in digital oxide superlattices
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DOI：
10.1038/nmat3405
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发表时间：
2012-10-01
期刊：
影响因子：
41.2
通讯作者：
Shen, Kyle M.
中科院分区：
文献类型：
--
作者：
Monkman, Eric J.;Adamo, Carolina;Shen, Kyle M.
控制界面的电子特性具有巨大的科学和技术意义，并且最近已从半导体扩展到具有母体材料中不存在的紧急基态的复合氧化物(1-5)。这些氧化物界面提供了一个全新的机会，可以通过设计量子多体相互作用来优化电子和磁性特性，而不是传统的带隙工程(5-7)。我们使用集成氧化物分子束外延和角分辨光电子能谱系统来合成和研究莫特绝缘体 LaMnO3 和能带绝缘体 SrMnO3 超晶格的电子结构。通过以原子层精度数字化改变 (LaMnO3)(2n)/(SrMnO3)(n) 超晶格中界面之间的间隔，我们证明了量子多体相互作用得到增强，将电子态从铁磁极化金属转变为赝能隙绝缘基态。这项工作展示了如何在相关氧化物界面上设计多体相互作用，这是在新型电子产品中利用此类效应的重要先决条件。
Controlling the electronic properties of interfaces has enormous scientific and technological implications and has been recently extended from semiconductors to complex oxides that host emergent ground states not present in the parent materials(1-5). These oxide interfaces present a fundamentally new opportunity where, instead of conventional bandgap engineering, the electronic and magnetic properties can be optimized by engineering quantum many-body interactions(5-7). We use an integrated oxide molecular-beam epitaxy and angle-resolved photoemission spectroscopy system to synthesize and investigate the electronic structure of superlattices of the Mott insulator LaMnO3 and the band insulator SrMnO3. By digitally varying the separation between interfaces in (LaMnO3)(2n)/(SrMnO3)(n) superlattices with atomic-layer precision, we demonstrate that quantum many-body interactions are enhanced, driving the electronic states from a ferromagnetic polaronic metal to a pseudogapped insulating ground state. This work demonstrates how many-body interactions can be engineered at correlated oxide interfaces, an important prerequisite to exploiting such effects in novel electronics.