Seminars & Lectures
* TITLE | Spin gap formation in 1D frustrated spin-orbital systems | ||||||
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* HOST(Applicant) | |||||||
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* DATE / TIME | 2004-05-03, 1:30 pm | ||||||
* PLACE | Bldg 3, Room #201, POSTECH | ||||||
* ABSTRACT | |||||||
To describe the spin-orbital energy gap formation in the one-dimensional symmetrically coupled spin-orbital model, we propose a simple mean field theory based on an SU(4) constraint fermion representation of spins and orbitals. A spin-orbital gapped phase is formed due to a marginally relevant spin-orbital valence bond pairing interaction. The energy gap of the spin and orbital excitations grows extremely slowly from the SU(4) symmetric point up to a maximum value and then decreases rapidly. By calculating the spin, orbital, and spin-orbital tensor static susceptibilities at zero temperature, we find a crossover from coherent to incoherent magnetic excitations as the spin-orbital coupling decreasing from large to small values. |