摘要

Existence of crystal surface and interface may reduce the spatial degrees of freedom of carriers, and thus results in various novel quantum phenomena related to the reduction of dimensionality. Measuring the electronic transport of a crystal surface and/or thin films thereon is very important not only to the potential application of materials but also to fundamental researches. It is highly desirable to obtain the electronic structure, morphology information and transport property of a material in situ, since they are strongly related. Based on a commercial apparatus equipped with scanning tunneling microscope (STM) and molecular beam epitaxy (MBE) system, we developed an surface-sensitive electronic transport measurement system that is compatible with the STM. A micro-four-point probe (MFPP) is utilized to increase the surface sensitivity in the transport measurement, which can be conducted at low temperature (Tmin=300 mK) and high magnetic field (Bmax=11 T). This new system was firstly used to measure FeSe thin film grown on SrTiO3(001) surface. The most exciting result is that we found its critical temperature (Tc) is as high as 109 K, which is much higher than Tc of any other iron-based superconductors found so far. This is also the first time to found a non-Cu-based superconductor with Tc higher than liquid-nitrogen temperature (77 K).

报告人简介

1999年毕业于中山大学物理系，获理学学士学位。2006年于日本东京大学物理系获理学博士学位。2006年至2010年在日本国立物质材料研究所从事博士后和研究员工作。2010年受聘于beat365中文版官方网站物理系任特别研究员。

主要研究内容：利用扫描隧道显微镜，光电子能谱及表面电导测量系统等表面分析与表征手段，探测以MBE法在晶体表面上生成的原子/分子（亚）单层及多层的低维纳米结构的原子排列与电子结构，探索原子/分子的自组织形成机制及其特有的电学与磁学特性，研究电子/自旋密度波，安德森局在及近藤效应等低维物理现象，在晶体表面/界面探寻新颖的量子现象，实现表面/界面低维体系的量子调控。