• 커뮤니티
  • 세미나/콜로퀴움
세미나/콜로퀴움

POSTECH PHYSICS SEMINAR(2008/02/13)

본문

"POSTECH PHYSICS SEMINAR




연 사 : Dr. B. J. Kim (University of Tokyo)

일 시 : 2008년 2월 13일(수) 오전 11시

장 소 : 공학3동 201호 (물리학과 세미나실)

제 목 : A relativistic Mott insulator Sr2IrO4 : An evidence from resonant x-ray scattering


[Abstract]


Relativistic spin-orbit coupling (SOC) gives rise to fascinating physical phenomena such as chiral magnetic ordering and spin-Hall effect, and allows electric control of an electron spin which forms a basis for spintronics in semiconductor devices. In the first part of this talk, I will discuss how a novel quantum state can be realized by SOC in a transition-metal oxide under strong crystal field in the presence of electron correlation effects. A 5d transition-metal oxide Sr2IrO4 reveals the novelJeff=1/2 Mott ground state having unique features unseen in conventional S=1/2 Mott insulator. The Jeff=1/2 state manifests relativistic effects with non-trivial spin-orbit mixed state and dominant orbital contribution to the magnetic moment.
In the second part, I will discuss how this state can be directly probed by resonant x-ray scattering (RXS) technique. RXS has proven a very powerful tool to study various kinds of ordering phenomena by exploiting resonance effects which selectively amplify signals that are otherwise undetectable. I demonstrate that this technique can be utilized to detect not only the ordering pattern but also theinternal details of an individual Jeff=1/2 moment.




문의 : 물리학과 박재훈 (054-279-2088, jhp@postech.ac.kr)
"
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