89 citations · 109 across the 2 of their papers we have counts for
7 papers
Conserving Approximations in Time-Dependent Density Functional Theory
Ulf von Barth, Nils Erik Dahlen, Robert van Leeuwen +1
In the present work we propose a theory for obtaining successively better approximations to the linear response functions of time-dependent density or current-density functional th…
Introduction to the Keldysh formalism and applications to time-dependent density-functional theory
Robert van Leeuwen, Nils Erik Dahlen, Gianluca Stefanucci +2
This paper gives an introduction to the Keldysh formalism, with emphasis on its usefulness in time-dependent density functional theory. In the first part we introduce the Keldysh c…
Antiferromagnetism in the Exact Ground State of the Half Filled Hubbard Model on the Complete-Bipartite Graph
Gianluca Stefanucci, Michele Cini
As a prototype model of antiferromagnetism, we propose a repulsive Hubbard Hamiltonian defined on a graph with and bonds…
The "W=0" Pairing Mechanism from Repulsive Interactions in Symmetric 2d Models
Michele Cini, Gianluca Stefanucci
In two-dimensional systems possessing a high degree of symmetry, the repulsive electron-electron interaction produces a pairing force; the mechanism would fail in the presence of s…
Canonical Transformation of the Hubbard Model and W=0 Pairing: Comparison with Exact Diagonalization Results
Michele Cini, Adalberto Balzarotti, Raffaella Brunetti +2
We have recently developed a canonical transformation of the Hubbard and related models, valid for systems of arbitrary size and for the full plane; this is particularly suited to…
Charge Conjugation and Pairing in a model CuO Cluster
Michele Cini, Adalberto Balzarotti, Gianluca Stefanucci
Highly-symmetric three-band Hubbard Cu-O clusters have peculiar properties when the hole number is such that they admit W=0 hole pairs. These are two-hole eigenstates of the on-sit…