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TT: Fachverband Tiefe Temperaturen

TT 61: Correlated Electrons: 1D Theory

TT 61.3: Talk

Wednesday, March 20, 2024, 17:00–17:15, H 3010

Influence of oxygen orbitals on the pairing behavior in the Emery model for doped ladders — •Gökmen Polat and Eric Jeckelmann — Institut für Theoretische Physik, Leibniz Universität Hannover

We investigate the Emery model on ladder-like lattices including two legs of copper d-orbitals and various numbers of oxygen p-orbitals. Various periodic ladder structures are considered with unit cells Cu_nO_m with ratio n/m from 2/5 to 2/3. We calculate gaps, pair binding energy, density distribution, and pairing correlation functions on ladders with open boundary conditions using the density matrix renormalization group (DMRG). We show that the presence or absence of chain-end p-orbitals can lead to the formation of localized boundary states and strongly influences the pairing properties at low doping. More generally, the pairing behavior of finite-size ladders upon hole or electron doping depends sensitively on which p-orbitals are included and on the strength of their hybridization with the copper d-orbitals. We show that these finite-size effects play a role in the apparent failure of the Emery model for cuprate ladders that has been reported recently [1].

[1] Song et al., Phys. Rev. B 107 (2023) L241108

Keywords: Emery model; ladder; pairing; DMRG