Dresden 2020 – wissenschaftliches Programm
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TT 62.5: Vortrag
Donnerstag, 19. März 2020, 16:00–16:15, HSZ 204
Dual parquet scheme for the two-dimensional Hubbard model: modelling low-energy physics of high-Tc cuprates with high momentum resolution — Grigory Astretsov1,2, •Georg Rohringer1,3, and Alexey Rubtsov1,2 — 1Russian Quantum Center — 2Lomonosov Moscow State University — 3University of Hamburg
We present a new method to treat the two-dimensional (2D) Hubbard model for parameter regimes which are relevant for the physics of the high-Tc superconducting cuprates. Our approach consists in the following three-step procedure: (i) High energy correlations are treated exactly by dynamical mean field theory (DMFT). From the DMFT solution we (ii) construct an effective low-energy model which depends only on the lowest Matsubara frequencies. We (iii) apply the two-particle self-consistent parquet formalism which takes into account the competition between different low-energy bosonic modes. In this way, we were able to map out the phase diagram of the 2D Hubbard model as a function of temperature and doping. Consistently with the experimental evidence for hole-doped cuprates and previous dynamical cluster approximation calculations, we find an antiferromagnetic region at low doping and a superconducting dome at higher doping. Our results also support the role of the van Hove singularity as an important ingredient for the high value of Tc at optimal doping. At small doping, the destruction of antiferromagnetism is accompanied by an increase of charge fluctuations supporting the scenario of a phase separated state driven by quantum critical fluctuations.