基于组合薄膜研究电子掺杂铜氧化物超导体的量子临界效应

项目名称： 基于组合薄膜研究电子掺杂铜氧化物超导体的量子临界效应

项目编号： No.11474338

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： 金魁

作者单位： 中国科学院物理研究所

项目金额： 110万元

中文摘要： 高温超导体机理的理解基于完整相图的建立。在铜氧化物母体中掺杂电子或者空穴都可以获得超导电性，然而二者的相图并不对称。要想建立统一的微观模型解释高温超导机理，实验上需要同时对空穴掺杂和电子掺杂铜氧化物开展系统深入的研究。早期由于样品的制约，对电子掺杂铜氧化物的研究远不如对空穴型掺杂体系深入。近年来，随着样品质量的大幅提高，对电子型铜氧化物的研究也逐渐深入。本项目将借鉴材料基因计划中的核心技术，即高通量组合薄膜技术，生长高质量外延电子型铜氧化物组合薄膜，充分发挥组合薄膜的并行快速制样、组分连续、氧可控等特点，通过快速的输运、隧道谱等测量手段，建立一幅以磁场、温度、化学组分、氧含量为变量的高纬度立体相图，全面深入研究电子型铜氧化物体系的量子临界效应，促进对电子型铜氧化物机理的理解。本项目将培训一批熟练掌握先进组合激光外延生长技术的研究生，同时为下一步利用组合薄膜技术探索新超导材料奠下基础。

中文关键词： 高温超导电性；超导薄膜；输运性质；量子相变；高通量组合薄膜

英文摘要： The understanding of the mechanism of high Tc superconductivity relies on well-established phase diagram. Superconductivity in cuprates could be achieved by charge doping, either electrons or holes, into the copper oxygen plane, whereas the phase diagram by electron- or hole- doping is highly asymmetric. In order to build a universal microscopic theory, systematic studies should be performed on both the electron-doped and the hole-doped cuprates. However, owing to the low quality of the samples the electron-doped ones have not been well addressed. Recently, the well improved sample quality makes the comprehension of electron-doped cuprates possible. In this proposed project, we will employ the key techniques of the Materials Genome Initiative project, i.e. the high throughput combinatorial thin film techniques, to synthesize phase-spread electron-doped cuprate thin films. By taking the advantage of the combinatorial thin films, such as high efficiency, sequential composition, and controllable oxygen content, measurements like transport, tunneling spectroscopy and so on will be used to explore a significant phase diagram as a function of field, temperature, doping, and oxygen variation. It is the first time that such a complex phase diagram will be destructed, which definitely helps the community to comprehend the quantum criticality and understand the mechanism. Using high-throughput combinatorial techniques to study the novel high-Tc superconductivity will supply a gap in China. This project will train several graduate students who will fit the Materials Genome Initiative project. Meanwhile, our unique high quality combinatorial thin films will bring us a worldwide cooperation. This project will lay a foundation for the search of new superconductors by high throughput combinatorial techniques.

英文关键词： High Tc superconductivity;Superconducting thin films;Transport properties;Quantum phase transitions;High throughput combinatorial thin films