Speakers: Jan Kuneš (Department of magnetism and superconductors, Institute of physics, Prague)
Place: Na Slovance, přednáškový sál v přízemí
Presented in English
Organisers:
Department of Condensed Matter Theory
Abstract: Using linear response formalism we have performed an unbiased search for particle-hole instabilities in the two-band Hubbard model close to the high-spin--low-spin transition. In addition to the previously reported Ising transition to an ordered arrangement of HS and LS sites we have found an instability towards condensation of spinful excitons. We will present numerical results obtained with dynamical mean-field theory as well as analytic expressions in the strong and weak coupling limits. We will discuss the symmetry aspects of the excitonic phase, connection to the physics of hard-core bosons, experimentally studied in the context of cold atoms, and possible implications for electronic materials.
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