Collective modes in excitonic magnets: dynamical mean-field study

0521051 - FZÚ 2020 RIV US eng J - Článek v odborném periodiku
Geffroy, D. - Kaufmann, J. - Hariki, A. - Gunacker, P. - Hausoel, A. - Kuneš, Jan
Collective modes in excitonic magnets: dynamical mean-field study.
Physical Review Letters. Roč. 122, č. 12 (2019), s. 1-6, č. článku 127601. ISSN 0031-9007. E-ISSN 1079-7114
Institucionální podpora: RVO:68378271
Klíčová slova: dynamical mea-field theory * Bethe-Salpeter equation * Goldstone mode * exctionic condensation
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)
Impakt faktor: 8.385, rok: 2019
Způsob publikování: Omezený přístup
https://doi.org/10.1103/physrevlett.122.127601

We present a dynamical mean-field study of dynamical susceptibilities in the two-band Hubbard model. Varying the model parameters we analyze the two-particle excitations in the normal as well as in the ordered phase, an excitonic condensate. The two-particle dynamical mean-field theory spectra in the ordered phase reveal the gapless Goldstone modes arising from spontaneous breaking of continuous symmetries. We also observe the gapped Higgs mode, characterized by vanishing of the gap at the phase boundary. Qualitative changes observed in the spin susceptibility can be used as an experimental probe to identify the excitonic condensation.

Trvalý link: http://hdl.handle.net/11104/0305707