PHYSICS/BK21 SEMINAR [6.22]

                “Simultaneous r-space and k-space probing
 of emergent phenomena in oxides and pnictides using STM ”

* Speaker : Dr. Jinho Lee(Brookhaven National Laboratory, USA)        
* Place : Physics Seminar Room (Science Bldg, 3-201)
* Date & Time : June  22 (Tue.)  4:00  ~  5:00 pm

* Abstract

For over decades, many intriguing emergent phenomena in strongly correlated electronic systems have been observed and remain as the most challenging problems in modern condensed matter physics. High Tc superconductivity in cuprates, nematicmetamagnetism 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 STM) techniques opened new possibility of exploring both r-space and k-space simultaneously in enormous precision, and became one of the most important tools to tackle such problems as this 23 year old puzzle.
For example, we can get local information like exact locations of impurities and dopants, or nano-scale electronic inhomogeniety which enable us to examine manybody 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, of calculations from DFE(density functional theory).
Furthermore, SI-STM can shed light to the question ‘which band is the most dominating band?’ in materials where many bands exist in great complexity.
In this talk, we apply various SI-STM technique to these siimingly different stronhly correlated materials, and try to understand differences as well as similarities by visualizing and comparing the results.

Contact Person : Prof. Han Woong Yeom  (054-279-2091, yeom@postech.ac.kr)