Title

Visualizing the interfacial quantum phases through light-matter interactions

Speaker

Prof. Cheng Cen

Institute of Physics, CAS

Time

2：30pm, January 17, 2025

Place

Material Science and Research Building B902

Cheng Cen is currently a professor at the Institute of Physics, Chinese Academy of Sciences. She received her Ph.D. in physics from University of Pittsburgh in 2010, worked in IBM Research until 2012, and then served as assistant and associate professor in the Department of Physics and Astronomy at West Virginia University until 2022. Her current research focuses on the nanoelectronic and nanophotonic properties of low-dimensional materials. She is a recipient of Career Awards from both US National Science Foundation and Department of Energy.

Abstract

Quantum phases at buried interfaces are often out of the reach of conventional characterization methods. In this talk, I will describe our recent works that employ light-matter interactions to decipher the microscopic natures of the interfacial quantum states. Using CTR-COBRA technique, we were able to map out the light-induced atomic displacements at FeSe/SrTiO₃ interfaces with a sub-Angstrom resolution. The data reveals two light-induced metastable structural traits, namely the out-of-plane corrugation of the Fe plane and the in-plane antiferrodistortive rotation of the Fe-trapezoid, that are not considered in the past but can strongly influence the electron pairing in FeSe. Additional studies of other low-dimensional superconducting material systems using both far-field and near-field scanning optical methods will also be discussed.