Prof. Donglai Feng [Fudan University]

Title:   Interfacial high temperature superconductivity studied by ARPES and STS

Time:  2:00 – 3:00 PM, June 19, 2015, Friday

Place: Conference room 201, Build 6, HPSTAR (Shanghai)

Host:  Dr. Xiao-Jia Chen

Abstract:

The discovery of high temperature superconductivity in single-layer FeSe/SrTiO3 provides a rich playground for exploring novel superconductivity in the ultra-thin limit. In this talk, I will show our recent progress in both tuning the superconductivity and studying the pairing symmetry of FeSe/SrTiO3.  By interfacial engineering, we were able to raise the superconducting gap opening temperature to 75 K in FeSe/BTO/STO heterostructure. Through in-situ STM studies, we investigated the superconductivity pairing symmetry of single layer FeSe by studying the quasi-particle interference (QPI) and impurity induced bound states, and demonstrate the plain s-wave paring symmetry for single-layer FeSe/SrTiO3. Moreover, I will introduce our new discovery of the signature of high temperature superconductivity near 60 K in electron doped Sr2IrO4 achieved through surface dosing technique.

Biography of the Speaker:

Prof. Donglai Feng works at Fudan University as a professor in Physics Department and the director of Key Laboratory of Applied Surface Physics. He was named as Distinguished Young Scholar from National Natural Science Foundation of China in 2002. He was employed as Chair Professor of Chang Jiang Scholars Program in 2006. His researches focus on the exploration for the novel phenomena and understanding of the fundamental issues of strongly correlated electron systems and complex quantum materials. He published more than 100 papers in popular journals such as Nature, Science, and Physical Review Letters, bringing about 5100 citations. During his research tenure, he has received many prestigious awards, including Young Scientist Award of United Nations Educational, Scientific and Cultural Organization (2005), Young Scientist Award of China (2006), Asian Achievement Award of Oversea Chinese Physical Society (2010), Academic Leading Expert of Shanghai (2010), C. N. Yang Award of The Association of Asia Pacific Physical Societies (2010), National 100 Excellent Ph. D Thesis Supervision Award of China (2011), Ye Qisun Physics Prize of the Physical Society of China (2011), and the first place of The Natural Science Award of Shanghai (2013) and so on. He has been serving Chair and Organizer of many international conferences on superconductivity and synchrotron radiation. He has been selected as the divisional associate editor of the Condensed Matter Physics Board of Physical Review Letters, the associate editor of Chinese Physical Letter, and the editorial committee member of Journal of Electron Spectroscopy and Related Phenomena.