Regensburg 2019 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 44: Correlated Electrons: Method Development
TT 44.1: Vortrag
Mittwoch, 3. April 2019, 15:00–15:15, H7
Dynamical susceptibility in DMFT: a sparse QMC sampling approach — •Dominique Geffroy1,2, Hiroshi Shinaoka3, Jan Kuneš2, Junya Otsuki4, Markus Wallerberger5, Emanuel Gull5, and Kazuyoshi Yoshimi6 — 1Department of Condensed Matter Physics, MU Brno, Czech Republic — 2Institute for Solid State Physics, TU Wien, Austria — 3Department of Physics, Saitama University, Japan — 4Department of Physics, Tohoku University, Japan — 5University of Michigan, Ann Arbor, USA — 6Institute for Solid State Physics, University of Tokyo, Japan
We discuss a new technique for the efficient sampling of two-particle correlation functions in the framework of dynamical mean-field theory. The approach is based on the expansion of the two-particle Green’s function, based on the recently introduced "intermediate representation" basis [1,2]. We demonstrate that both the complex low-frequency structure, and the high-frequency tails are correctly described.
This sparse sampling can be used for the calculation of dynamic susceptibilities, after inversion of the Bethe-Salpeter equation. We present results in the context of the BEC to BCS crossover [3, 4] in the vicinity of the excitonic condensation in the two-band Hubbard model [5].
H. Shinaoka, J. Otsuki et. al., Phys. Rev. B 96, 035147 (2017)
H. Shinaoka, J. Otsuki et al., Phys. Rev. B 97, 205111 (2018)
B. Zenker, D. Ihle et al., Phys. Rev. B 85, 121102(R) (2012)
J. Kuneš, J. Phys.: Cond. Mat. 27, 333201 (2015)
D. Geffroy, J. Kaufmann et al., arXiv 1808.08046 (2018)