We study the effect of buckling and breathing phonons, relevant for cuprate superconductors, on the d-wave superconductivity in the two-dimensional Hubbard model by employing dynamical cluster Monte Carlo calculations. The interplay of electronic correlations and the electron-phonon interaction produces two competing effects: an enhancement of the effective d-wave pairing interaction, which favors d-wave superconductivity, and a strong renormalization of the single-particle propagator, which suppresses superconductivity. In the region of the parameter space relevant for cuprate superconductors, we find that the buckling and the breathing phonons suppress the superconductivity.We study the effect of buckling and breathing phonons, relevant for cuprate superconductors, on the d-wave superconductivity in the two-dimensional Hubbard model by employing dynamical cluster Monte Carlo calculations. The interplay of electronic correlations and the electron-phonon interaction produces two competing effects: an enhancement of the effective d-wave pairing interaction, which favors d-wave superconductivity, and a strong renormalization of the single-particle propagator, which suppresses superconductivity. In the region of the parameter space relevant for cuprate superconductors, we find that the buckling and the breathing phonons suppress the superconductivity.

arXiv:cond-mat/0611067Journal of Physics Condensed MatterOct 31, 20129 citations

From the Cuprate Compounds to the Hubbard Model

Lecture notes in physics. M, MonographsNov 28, 20080 citations

Effect of adiabatic phonons on striped and homogeneous ground states

Yucel Yildirim, Adriana Moreo

The effects of adiabatic phonons on a spin-fermion model for high ${T}_{c}$ cuprates are studied using numerical simulations. In the absence of electron-phonon interactions (EPI), stripes in the ground state are observed [C. Buhler, S. Yunoki, and A. Moreo, Phys. Rev. Lett. 84, 2690 (2000); Phys. Rev. B. 62, R3620 (2000)] for certain dopings while homogeneous states are stabilized in other regions of parameter space. Different modes of adiabatic phonons are added to the Hamiltonian: breathing, shear, and half-breathing modes. Diagonal and off-diagonal electron-phonon couplings are considered. It is observed that strong diagonal EPI generate stripes in previously homogeneous states, while in striped ground states an increase in the diagonal couplings tends to stabilize the stripes, inducing a gap in the density of states (DOS) and rendering the ground state insulating. The off-diagonal terms, on the other hand, destabilize the stripes creating inhomogeneous ground states with a pseudogap at the chemical potential in the DOS. The breathing mode stabilizes static diagonal stripes; while the half-breathing (shear) modes stabilize dynamical (localized) vertical and horizontal stripes. The EPI induces decoherence of the quasiparticle peaks in the spectral functions.The effects of adiabatic phonons on a spin-fermion model for high ${T}_{c}$ cuprates are studied using numerical simulations. In the absence of electron-phonon interactions (EPI), stripes in the ground state are observed [C. Buhler, S. Yunoki, and A. Moreo, Phys. Rev. Lett. 84, 2690 (2000); Phys. Rev. B. 62, R3620 (2000)] for certain dopings while homogeneous states are stabilized in other regions of parameter space. Different modes of adiabatic phonons are added to the Hamiltonian: breathing, shear, and half-breathing modes. Diagonal and off-diagonal electron-phonon couplings are considered. It is observed that strong diagonal EPI generate stripes in previously homogeneous states, while in striped ground states an increase in the diagonal couplings tends to stabilize the stripes, inducing a gap in the density of states (DOS) and rendering the ground state insulating. The off-diagonal terms, on the other hand, destabilize the stripes creating inhomogeneous ground states with a pseudogap at the chemical potential in the DOS. The breathing mode stabilizes static diagonal stripes; while the half-breathing (shear) modes stabilize dynamical (localized) vertical and horizontal stripes. The EPI induces decoherence of the quasiparticle peaks in the spectral functions.

arXiv:cond-mat/0503292Physical Review BOct 20, 20053 citations

The effects of adiabatic phonons on a spin-fermion model for high

{T}_{c}

cuprates are studied using numerical simulations. In the absence of electron-phonon interactions (EPI), stripes in the ground state are observed [C. Buhler, S. Yunoki, and A. Moreo, Phys. Rev. Lett. 84, 2690 (2000); Phys. Rev. B. 62, R3620 (2000)] for certain dopings while homogeneous states are stabilized in other regions of parameter space. Different modes of adiabatic phonons are added to the Hamiltonian: breathing, shear, and half-breathing modes. Diagonal and off-diagonal electron-phonon couplings are considered. It is observed that strong diagonal EPI generate stripes in previously homogeneous states, while in striped ground states an increase in the diagonal couplings tends to stabilize the stripes, inducing a gap in the density of states (DOS) and rendering the ground state insulating. The off-diagonal terms, on the other hand, destabilize the stripes creating inhomogeneous ground states with a pseudogap at the chemical potential in the DOS. The breathing mode stabilizes static diagonal stripes; while the half-breathing (shear) modes stabilize dynamical (localized) vertical and horizontal stripes. The EPI induces decoherence of the quasiparticle peaks in the spectral functions.