Colloquium

Department of Physics & Astronomy

Simultaneous r-space and k- space probing of emergent phenomena in correlated electron systems using SI-STM

May 9, 2012l Hit 1007
Date : May 9, 2012 16:00 ~
Speaker : Prof. Jinho Lee(Physics/SNU)
Professor :
Location : 56동106호
For over decades, many intriguing emergent phenomena in strongly correlated electron systems (CES) have been observed and remain as the most challenging problems in modern condensed matter physics. High-Tc superconductivity in cuprates, nematic meta-magnetism in ruthenates and newly found superconductivity in pnictide family are among those examples. Especially, more than 20 years have been passed since high- Tc superconductivity was discovered, but still its mechanism is illusive.
However, recent advances in SI-STM(spectroscopic-imaging scanning tunneling microscopy) techniques opened new possibility of exploring both r-space and k-space simultaneously in enormous precision as well as measuring electron-boson interactions , making SI-STM one of the most versatile tools in study of CES.
For example, we can get local information like exact locations of impurities and dopants , or nano-scale electronic inhomogeniety which enables us to examine many-body theoretical predictions , at the same time probing relevant band structure with meV energy resolution which we can compare to the results from other collective probes like dHv Alphen effect and ARPES , , or calculations from DFT(density functional theory)1. Furthermore, SI-STM can shed light to the question “which band is the most dominating band?” in materials where many bands exist in great complexity1.
In this talk, we apply various SI-STM technique to these seemingly different strongly correlated materials, and try to understand differences as well as similarities by visualizing and comparing the results. New STM results on pseudo-gap (PG) phase of superconducting cuprates will be also presented .