“Spectroscopic studies of iron-based superconductors : what have we learned?”

Apr. 08 (Fri.), 4:00 PM, E6-2. 5st fl. #1501
Dr. Changyoung Kim, SEOUL NATIONAL UNIV.

As in the cases for other materials, measuring the electronic structures is the first step towards understanding the microscopic mechanism for the superconductivity in of iron-based superconductors (IBS). Angle resolved photoelectron spectroscopy (ARPES) has played a key role in the studies of IBS, from band structure determination to superconducting gap measurements.

In this presentation, I will give an overview on the spectroscopic studies of IBS by using ARPES including recent progress on 100K superconductivity in mono-layer FeSe. I will start with a brief description of the general electronic structures (band dispersions and Fermi surfaces) and orbital characters of bands measured by ARPES. The main part of the presentation will be on two subjects, namely, nematic order and mono-layer superconductivity. The anisotropic electronic structure of the nematic order can be investigated by ARPES. In addition, ARPES is also surface sensitive which makes it suitable for the study of mono-layer superconductivity. I will discuss our recent work on these two subjects along with results from other groups.

Contact: Eun Gook Moon, Physics Dept., (egmoon@kaist.ac.kr)