Berlin 2018 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 42: Charge Order

TT 42.2: Vortrag

Dienstag, 13. März 2018, 10:30–10:45, HFT-FT 131

Density Matrix Renormalization Group Study of the Two-Dimensional Hubbard Model in Hybrid Real-Momentum Space — •Georg Ehlers and Reinhard M. Noack — Philipps Universität Marburg

We investigate the square-lattice Hubbard model in hybrid real-momentum space using the density matrix renormalization group (DMRG). The variation of the DMRG that we use is formulated for lattices with cylindrical geometry and utilizes the conserved transverse lattice momentum. Compared to the standard real-space algorithm, it achieves a speedup that scales quadratically with the width of the lattice [G. Ehlers et al., Phys. Rev. B 95, 125125 (2017)]. For width-four and width-six cylinders at one-eighth doping and Coulomb interaction strengths U/t=8 and U/t=4, we find a striped ground state. In a combined study with other state-of-the-art numerical methods, we provide strong evidence that the striped state is present in a substantial region of the underdoped regime of the ground-state phase diagram of the two-dimensional Hubbard model. The periodicity and stripe filling of our striped state differs from that found experimentally in hole-doped cuprates, indicating that terms beyond the standard Hubbard model must be included to accurately model high-temperature superconductivity [1].
B.-X. Zheng et al., Science 358, 1155 (2017).