Density matrix renormalization group based downfolding of the three-band Hubbard model: Importance of density-assisted hopping

Physical review. B./Physical review. B, Journal Year: 2023, Volume and Issue: 108(16)

Published: Oct. 24, 2023

Typical Wannier-function downfolding starts with a mean-field or density functional set of bands to construct the Wannier functions. Here, we carry out controlled approach, using matrix renormalization group computed natural orbital bands, downfold three-band Hubbard model an effective single-band model. A sharp drop-off in occupancy at edge first band provides clear justification for Constructing functions from band, compute all possible two-particle terms and retain those significant magnitude. The resulting includes two-site density-assisted hopping ${t}_{n}\ensuremath{\sim}0.6t$. These lead reduction ratio $U/{t}_{\mathrm{eff}}$, are important capturing doping-asymmetric carrier mobility, as well enhancing pairing hole-doped cuprates.

Language: Английский

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Influence of oxygen orbitals and boundary conditions on the pairing behavior in the Emery model for doped ladders

Physical review. B./Physical review. B, Journal Year: 2025, Volume and Issue: 111(12)

Published: March 17, 2025

We investigate the Emery model on several ladder-like lattices including two legs of copper d orbitals and various numbers oxygen p orbitals. Pair binding energy, pair spatial structure, density distribution, pairing correlation functions are calculated using density-matrix renormalization group (DMRG). show that a Luther-Emery phase with enhanced correlations can be found for hole doping as well electron realistic parameters. Ladder properties depend sensitively parameters, p taken into account, boundary conditions. The energy is more reliable quantity than ascertaining occurrence in ladders. Overall, our results two-leg ladders support possibility superconductivity hole-doped 2D model. issue rather to determine which ladder structures parameters appropriate approximate two-dimensional cuprates. Published by American Physical Society 2025

Language: Английский

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Valence transition theory of the pressure-induced dimensionality crossover in superconducting Sr14−xCaxCu24O41

Physical review. B./Physical review. B, Journal Year: 2023, Volume and Issue: 108(13)

Published: Oct. 23, 2023

One of the strongest justifications for continued search superconductivity within single-band Hubbard Hamiltonian originates from apparent success ladder-based theories in predicting occurrence cuprate coupled-ladder compound ${\mathrm{Sr}}_{14\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{Cu}}_{24}{\mathrm{O}}_{41}$. Recent theoretical works have, however, shown complete absence quasi-long-range superconducting correlations hole-doped multiband ladder including realistic Coulomb repulsion between holes on oxygen sites and oxygen-oxygen hole hopping. Experimentally, ${\mathrm{Sr}}_{14\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{Cu}}_{24}{\mathrm{O}}_{41}$ occurs only under pressure is preceded by dramatic transition one to two dimensions that remains not understood. We show understanding dimensional crossover requires adopting a valence model which there Cu-ion ionicity $+2$ $+1$, with transfer Cu O ions [S. Mazumdar, Phys. Rev. B 98, 205153 (2018)]. The driving force behind closed-shell electron configuration ${\mathrm{Cu}}^{1+}$, feature shared cations all oxides negative charge-transfer gap. make falsifiable experimental prediction discuss implications our results layered two-dimensional cuprates.

Language: Английский

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Computational demonstrations of density wave of Cooper pairs and paired-electron liquid in the quarter-filled band—A brief review

Chaos An Interdisciplinary Journal of Nonlinear Science, Journal Year: 2024, Volume and Issue: 34(7)

Published: July 1, 2024

There has been strong interest recently in the so-called Cooper pair density wave, subsequent to proposition that such a state occurs hole-doped cuprate superconductors. As of now, there is no convincing demonstration theoretical literature. We present here brief but complete review our and computational work on paired-electron crystal (PEC), which also experimentally seen insulating phase proximate superconductivity (SC) organic charge-transfer solid (CTS) Within theory, SC CTS does indeed evolve from PEC. A crucial requirement for finding PEC proper carrier one charge per two sites taken into consideration at outset. Following discussion superconductors, we briefly discuss how theory can be extended understand diagram superconductors remained mysterious after nearly four decades discovery this family.

Language: Английский

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