Seminars & Lectures
|* TITLE||The role of Hund's coupling on approach to metal insulator transition in NiS2−xSex|
|* DATE / TIME||2021-04-12, 15:00-16:00|
|* PLACE||Online (ZOOM) & APCTP Seminar Rm#512|
|Understanding the characteristic energy scale is a fundamental issue in a strongly correlated electron system. In the multiband system, the energy scale is not only affected by the effective Coulomb interaction but also by the Hund’s coupling. In an angle resolved photoemission spectroscopy of NiS2-xSex system the evolution of kink has been observed, and a dynamical mean field theory calculation combined with density functional theory confirm that this kink is originated from Hund’s coupling.[1,2] The abrupt deviation from the Fermi liquid behavior in the electron self-energy makes kink features at low energy scale and this kink is directly related to the coherence-incoherence crossover temperature scale. The evolution of the characteristic temperature scale via kink features in the spectral function is the hallmark of Hund’s physics in the multiorbital system.
 C.-Y. Moon et al. Physical Review B 92, 235130 (2015).
 B.G. Jang et al. Nature Communications 12, 1208 (2021).
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