Recently, quantum materials are the hottest topic in condensed matter physics. As the samples become smaller and smaller, in situ characterizations become more and more important. By combining molecular beam epitaxy (MBE) with STM, ARPES and other techniques, in situ characterizations can be achieved. With atomic precision control of growth, MBE can provide clean and smooth surfaces for STM and ARPES to study. Meanwhile, STM, ARPES and in situ techniques can also provide enough information for MBE to eliminate much of the trial and error during growth, so that one can fabricate the structures that do not exist in nature or cannot be grown by other techniques. Therefore, this kind of combined system can do some unique work which cannot be done by separate instruments.

In this talk, I will introduce several works done with the combined system to demonstrate the strong power of the combination. With help of STM, artificial cluster crystals, i.e. a periodical array of identical nanoclusters can be grown with precise control. Atomically flat Pb thin films, stanene etc. can be grown with MBE and studied with STM. In Pb films on Si(111), we found quantum well states (QWS) form due to the electronic confinement in the film normal direction and novel properties induced by QWS. We also found high quality topological insulator films can be grown with MBE. Standing waves and Landau levels were observed with low temperature STM and demonstrated the existing of the topological surface states and the prohibition of backward-scattering. Topological insulator/superconductor hetero structures are also fabricated for exploring Majorana fermions.

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Bio：贾金锋，1987年本科毕业于北京大学物理系，1992年北京大学物理系获博士学位，现任上海交通大学讲席教授。在SCI收录的杂志上发表文章250多篇，文章被引用11000多次，被选为2018年Highly cited research（Clarivate Analytics）。曾获2016年教育部自然科学一等奖，2013年全球华人物理学会“亚洲成就奖”，2011年国家自然科学二等奖（第一获奖人）；2011年香港求是科技基金会“杰出科技成就集体奖”； 2004年国家自然科学二等奖（第三获奖人）；2003年北京市科学技术奖一等奖； 1997年国家教育委员会科技进步一等奖等重要奖项。国家杰出青年基金获得者（2003）、国家教育部“长江学者奖励计划”特聘教授（2009）。