All-oxide epitaxial heterostructures for the generation and electric field control of topological spin textures

拓扑自旋结构的电场操纵是这一建议的主要驱动力。为了实现这一点，必须在绝缘或坏金属的材料中稳定拓扑磁性织构，例如一些钙钛矿金属氧化物。然而，定制物质物理性质的独特有力手段是设计人工结构，例如外延异质结构，其中发生结构调节和界面耦合，其与破缺的反转对称性一起，强烈地影响异质结构的性质，通常导致新的性质。在特定类型的外延异质结构，我们在这里探索，我们的目标是利用：由于接口，磁各向异性（作为磁晶各向异性和薄膜生长相关的各向异性的组合）在铁磁氧化物层，和Dzyaloshinskiii-Moriya相互作用的固有反转对称性破缺与大自旋轨道耦合的氧化物在界面处。由于界面张力和磁各向异性的大小都是可调的，因此我们必须探索哪些氧化物钙钛矿层的组合容易形成拓扑自旋结构，电场对拓扑自旋织构的控制将在背栅电场对异质结构的霍尔电阻率的影响和高分辨率透射电子显微镜中的原位偏置实验中进行研究。

Electric field-manipulation of topological spin structures is the main driving force for this proposal. In order to achieve this, topological magnetic textures have to be stabilized in materials that are insulating or bad metals, such as some perovskite metal oxides.A uniquely powerful means to tailor physical properties of matter, however, is to design artificial structures such as epitaxial heterostructures, in which structural accommodations and interfacial coupling occur, which, together with the broken inversion symmetry, strongly influence the properties of the heterostructures, often resulting in novel properties. In the particular types of epitaxial heterostructures that we explore here, we aim to make use of: inherent inversion symmetry breaking due to interfacing, magnetic anisotropy (as a combination of magneto-crystalline anisotropy and thin film growth related anisotropy) in a ferromagnetic oxide layer, and the Dzyaloshinskii-Moriya interaction (DMI) at the interface with an oxide with large spin-orbit coupling. Both the magnitude of the interfacial DMI and the magnetic anisotropy are tunable and thus we have to explore which combinations of oxide perovskite layers would be susceptible to form topological spin structures.The control of topological spin textures by electric fields will be studied in backgate electric field effects on Hall resistivity of the heterostructures and in situ biasing experiments in the high resolution transmission electron microscope.