Orbital-adapted electronic structure and anisotropic transport in gamma-A1(2)O(3)/SrTiO3 heterostructure
Orbital-adapted electronic structure and anisotropic transport in gamma-A1(2)O(3)/SrTiO3 heterostructure
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γ-A1(2)O(3)/SrTiO3 异质结构中的轨道适应电子结构和各向异性输运
DOI：
10.1103/physrevmaterials.4.016001
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发表时间：
2020
影响因子：
3.4
通讯作者：
Gang Wu
中科院分区：
文献类型：
--
作者：
Xiaoping Yang;Haibin Su;Gang Wu
High electron mobility is pivotal in engineering oxide interfaces for electronic devices. Here, interfacial structure and physical behaviors ofspinel/perovskite heterostructure are explored to understand the microscopic origin of its extremely high electron mobilityat 2 K). Lattice mismatch at interface and intrinsic Al cation vacancies result in unexpected interfacial reconstruction and anisotropic electronic behavior. The spontaneous polarization in thepart leads to an insulator-metal transition observed experimentally, even if the thickness ofis only one unit cell, and a strong internal electric field can be as large as 142 mV/Å, roughly 1.8 times the experimentally observed value of 80.1 mV/Å in. As a result, unlike only in-plane slightly occupiedsubbands in the conventional-based perovskite/perovskite heterostructure, all threeorbitals have charge exchange with the surfacialorbitals in; especially, the preferential orbital occupation is out-of-planeat the interface. Nontrivial orbital occupation and complicated interfacial reconstruction result in large group velocity and a high density of states at the Fermi level and therefore serve as the origins of extremely high electron mobility and high carrier concentration. The physical mechanism revealed in our work offers insight into the creation of high-mobility nanoscale electronic devices.
