82 citations · 969 across the 61 of their papers we have counts for
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Ring-like shaped charge modulations in the t-J model with long-range Coulomb interaction
Matías Bejas, Roland Zeyher, Andrés Greco
The study of the charge excitations in cuprates is presently an interesting topic because of the development of new and precise x-ray experiments. Based on a large- formulation…
Crossover between electron-electron and electron-phonon mediated pairing on the Kagome lattice
Xianxin Wu, Debmalya Chakraborty, Andreas P. Schnyder +1
We study electron-electron and electron-phonon mediated pairing in the Holstein extended Hubbard model on the Kagome lattice near the van Hove fillings, and investigate their combi…
Gapped collective charge excitations and interlayer hopping in cuprate superconductors
M. Hepting, M. Bejas, A. Nag +17
We use resonant inelastic x-ray scattering (RIXS) to probe the propagation of plasmons in the electron-doped cuprate superconductor SrLaCuO (SLCO). We detect a…
Electron self-energy from quantum charge fluctuations in the layered t-J model with long-range Coulomb interaction
Hiroyuki Yamase, Matías Bejas, Andrés Greco
Employing a large-N scheme of the layered t-J model with the long-range Coulomb interaction, which captures fine details of the charge excitation spectra recently observed in cupra…
Detection of Acoustic Plasmons in Hole-Doped Lanthanum and Bismuth Cuprate Superconductors Using Resonant Inelastic X-Ray Scattering
Abhishek Nag, M. Zhu, Matias Bejas +11
High Tc superconductors show a rich variety of phases associated with their charge degrees of freedom. Valence charges can give rise to charge ordering or acoustic plasmons in thes…
Ferromagnetic fluctuations in the Rashba-Hubbard model
Andrés Greco, Matías Bejas, Andreas P. Schnyder
We study the occurrence and the origin of ferromagnetic fluctuations in the longitudinal spin susceptibility of the --Rashba-Hubbard model on the square lattice. The combine…
Translation-Invariant Parent Hamiltonians of Valence Bond Crystals
Daniel Huerga, Andres Greco, Claudio Gazza +1
We present a general method to construct translation-invariant and SU(2) symmetric antiferromagnetic parent Hamiltonians of valence bond crystals (VBC). The method is based on a ca…
Charge-Density-Excitation Spectrum in the t-t'-J-V Model
Andres Greco, Hiroyuki Yamase, Matias Bejas
We study the density-density correlation function in a large-N scheme of the t-t'-J-V model. When the nearest-neighbor Coulomb interaction V is zero, our model exhibits phase separ…
Plasmon excitations in layered high-Tc cuprates
Andres Greco, Hiroyuki Yamase, Matias Bejas
Motivated by the recent resonant inelastic x-ray scattering (RIXS) experiment for the electron-doped cuprates Nd_{2-x}Ce_{x}CuO_{4} with x around 0.15, we compute the density-densi…
-wave bond-order charge excitations in electron-doped cuprates
Hiroyuki Yamase, Matías Bejas, Andrés Greco
We study charge excitation spectra in the two-dimensional - model on a square lattice to explore a charge-order tendency recently found in electron-doped cuprates around the…
Possible charge instabilities in two-dimensional doped Mott insulators
Matias Bejas, Andres Greco, Hiroyuki Yamase
Motivated by the growing evidence of the importance of charge fluctuations in the pseudogap phase in high-temperature cuprate superconductors, we apply a large-N expansion formulat…
Path integrals for dimerized quantum spin systems
Adriana Foussats, Andres Greco, Alejandro Muramatsu
Dimerized quantum spin systems may appear under several circumstances, e.g\ by a modulation of the antiferromagnetic exchange coupling in space, or in frustrated quantum antiferrom…
Role of dynamical non-double-occupancy excitations on the quasiparticle damping of the model in the large- limit
A. Foussats, A. Greco, M. Bejas
One-electron self-energy in the - model was computed using a recently developed large- method based on the path integral representation for Hubbard operators. One of the m…
Self-energy renormalization around the flux phase in the model: Possible implications in underdoped cuprates
Andrés Greco
The flux phase predicted by the model in the large-N limit exhibits features that make it a candidate for describing the pseudogap regime of cuprates. However certain propert…
model one-electron renormalizations: high energy features in photoemission experiments of high- cuprates
Andrés Greco
Recent angle-resolved photoemission experiments in hole doped cuprates reported new and interesting high energy features which may be useful for understanding the electronic proper…
Charge order and phonon renormalizations: Possible implications for cobaltates
M. Bejas, A. Greco, A. Foussats
Several experimental and theoretical studies in cobaltates suggest the proximity of the system to charge ordering (CO). We show, qualitatively, in the frame of a model couple…
Electron-phonon interaction dressed by electronic correlations near charge ordering as the origin for superconductivity in cobaltates
A. Foussats, A. Greco, M. Bejas +1
We consider possible routes to superconductivity in hydrated cobaltates Na_xCoO_2.yH_2O on the basis of the t-J-V model plus phonons on the triangular lattice. We studied the stabi…
Collective excitations in unconventional charge-density wave systems
A. Greco, R. Zeyher
The excitation spectrum of the t-J model is studied on a square lattice in the large limit in a doping range where a -- (DDW) forms below a transition tempera…
Non-Fermi liquid behavior in nearly charge ordered layered metals
J. Merino, A. Greco, N. Drichko +1
Non-Fermi liquid behavior is shown to occur in two-dimensional metals which are close to a charge ordering transition driven by the Coulomb repulsion. A linear temperature dependen…
Large-N expansion based on the Hubbard operator path integral representation and its application to the t-J model II. The case for finite
Adriana Foussats, Andrés Greco
We have introduced a new perturbative approach for model where Hubbard operators are treated as fundamental objects. Using our vertices and propagators we have developed a…
Spin exchange and superconductivity in a model for two-dimensional quarter-filled systems
Andres Greco, Jaime Merino, Adriana Foussats +1
The effect of antiferromagnetic spin fluctuations on two-dimensional quarter-filled systems is studied theoretically. An effective model on a square lattice which accounts…
Low-Frequency Optical Properties of -(BEDO- TTF)[CsHg(SCN)]: Indications of Electronic Correlations in a 1/5-Filled Two-Dimensional Conductor
N. Drichko, K. Petukhov, M. Dressel +5
The polarized reflectivity of -(BEDO-TTF)[CsHg(SCN)] is studied in the infrared range between 60 cm-1 and 6000 cm-1 from room temperature down to 10 K…
Dynamical properties of a strongly correlated model for quarter-filled layered organic molecular crystals
J. Merino, A. Greco, R. H. Mckenzie +1
The dynamical properties of an extended Hubbard model, which is relevant to quarter-filled layered organic molecular crystals, are analyzed. We have computed the dynamical charge c…
Large-N expansion based on the Hubbard-operator path integral representation and its application to the model
Adriana Foussats, Andres Greco
In the present work we have developed a large-N expansion for the model based on the path integral formulation for Hubbard-operators. Our large-N expansion formulation contai…