过渡金属氧化物界面二维电子态的量子输运与调控研究

项目名称： 过渡金属氧化物界面二维电子态的量子输运与调控研究

项目编号： No.11474022

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 聂家财

作者单位： 北京师范大学

项目金额： 100万元

中文摘要： 探究过渡金属氧化物异质界面二维电子态形成的物理机制，以及寻找高电导性、高迁移率的新型氧化物异质界面体系，是目前低维量子功能材料研究的一大重点。在本课题中，我们将通过原子分辨扫描透射电子显微镜、电子能量损失谱、X射线光电子能谱并结合第一性原理计算揭示LaAlO3/SrTiO3和CrO2/TiO2界面二维电子态的起源；利用物理特性测量系统等测量氧化物异质结界面在低温和外加磁场下的磁阻振荡、郎道能级和霍尔效应等输运特性，探测超导、铁磁和量子霍尔相等新奇量子态，并结合理论揭示其物理本质。利用聚合物离子液体的方法对上述界面施加门电压，调控界面的载流子浓度，探测其电子迁移率随门电压也就是载流子浓度的变化情况，为异质结电子器件的设计和制备提供充分的实验依据。

中文关键词： 二维电子态；过渡金属氧化物；界面；量子霍尔电导；迁移率

英文摘要： The search for the origin of two-dimensional electron state (2DES) at transition metal oxide heterostructure interfaces, and for new oxide heterostructure interface system with high conductivity and high mobility, is currently one of the most active research fields in low-dimensional quantum functional materials. In this study, atomic-resolution scanning transmission electron microscopy, electron energy loss spectroscopy, X-ray photoelectron spectroscopy and first-principles calculation will be employed in combination to investigate the origin of 2DES at LaAlO3/SrTiO3 and CrO2/TiO2 interfaces. Meantime, magnetoresistance oscillations, Landau levels and Hall effect will be measured by Physical Property Measurement System, to explore novel quantum states, such as superconductivity, ferromagnetism, and quantum Hall phases, in combination with the theory to reveal their physical nature. By applying a gate voltage, carrier concentration of the interfaces will be controlled and the relationship between electron mobility and applied electrical field (i.e., carrier concentration) will be systematically investigated, demonstrating a route to the design and preparation of heterojunction electronic devices.

英文关键词： 2DES;Transition Metal Oxide;Interface;Quantum Hall Conductance;Mobility