Chatterjee Shouvik, Khalid Shoaib, Inbar Hadass S, Goswami Aranya, Guo Taozhi, Chang Yu-Hao, Young Elliot, Fedorov Alexei V, Read Dan, Janotti Anderson, Palmstrøm Chris J
Department of Electrical and Computer Engineering, University of California, Santa Barbara, CA 93106, USA.
Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India.
Sci Adv. 2021 Apr 14;7(16). doi: 10.1126/sciadv.abe8971. Print 2021 Apr.
Controlling electronic properties via band structure engineering is at the heart of modern semiconductor devices. Here, we extend this concept to semimetals where, using LuSb as a model system, we show that quantum confinement lifts carrier compensation and differentially affects the mobility of the electron and hole-like carriers resulting in a strong modification in its large, nonsaturating magnetoresistance behavior. Bonding mismatch at the heteroepitaxial interface of a semimetal (LuSb) and a semiconductor (GaSb) leads to the emergence of a two-dimensional, interfacial hole gas. This is accompanied by a charge transfer across the interface that provides another avenue to modify the electronic structure and magnetotransport properties in the ultrathin limit. Our work lays out a general strategy of using confined thin-film geometries and heteroepitaxial interfaces to engineer electronic structure in semimetallic systems, which allows control over their magnetoresistance behavior and simultaneously provides insights into its origin.
通过能带结构工程控制电子特性是现代半导体器件的核心。在此，我们将这一概念扩展到半金属，以LuSb作为模型系统，我们表明量子限制消除了载流子补偿，并对电子和类空穴载流子的迁移率产生不同影响，从而导致其大的、非饱和磁阻行为发生强烈改变。半金属（LuSb）和半导体（GaSb）异质外延界面处的键合失配导致二维界面空穴气的出现。这伴随着界面上的电荷转移，为在超薄极限下改变电子结构和磁输运特性提供了另一条途径。我们的工作提出了一种利用受限薄膜几何结构和异质外延界面来设计半金属系统电子结构的通用策略，这使得能够控制其磁阻行为，并同时深入了解其起源。
