Related papers: A Hartree-Fock Study of Persistent Currents in Dis…
We perform two types of {\it ab initio} perturbation calculations of effective interactions in the Hartree--Fock (HF) basis instead of the harmonic-oscillator basis: one is called the Brillouin--Wigner (BW) perturbation and another is…
In this paper, a generalization of standard spin fluctuation theory is considered by replacing the simple Hubbard interaction by the screened Hartree-Fock interaction for f electrons. This model is then used in both an LS and a JJ coupling…
We report the solution of the persistent current in two coupled rings in the presence of external magnetic fluxes. We showed that the magnetic fluxes modify the global phase of the electronic wave function for multiple connected geometry…
The symmetry-projected Hartree--Fock ansatz for the electronic structure problem can efficiently account for static correlation in molecules, yet it is often unable to describe dynamic correlation in a balanced manner. Here, we consider a…
We present unrestricted Hartree Fock method coupled with configuration interaction (CI) method (URHF-CI) suitable for the calculation of ground and excited states of large number of electrons localized by complex gate potentials in…
The magnetic Hartree Fock ground state stability for a two-dimensional interacting electron system with Rashba-type coupling is studied by implementing the standard many body Green's function formalism. The externally applied electrical…
We explore the behavior of persistent current and low-field magnetic response in mesoscopic one-channel rings and multi-channel cylinders within the tight-binding framework. We show that the characteristic properties of persistent current…
We study the dynamics of magnetic correlations in the half-filled fermionic Hubbard model following a fast ramp of the repulsive interaction. We use Schwinger-Keldysh self-consistent second-order perturbation theory to investigate the…
We study a systematic improvement of perturbation theory for gauge fields on the lattice [hep-lat/0606001]; the improvement entails resumming, to all orders in the coupling constant, a dominant subclass of tadpole diagrams. This method,…
We investigate the distribution of the electron density and the potential in a quantum wire coupled to reservoirs, treating this structure as a unified quantum system and taking into account the Coulomb interaction of electrons. The…
We show that several novel effects related to persistent currents can arise in open systems, which have no analogue in closed or isolated systems. We have considered a system of a metallic ring coupled to two electron reservoirs. We show…
We develop a Luttinger liquid theory of the Coulomb drag of persistent currents flowing in concentric mesoscopic rings, by incorporating non-linear corrections to the electron dispersion relation. We demonstrate that at low temperatures,…
The Hund's-rule-exchange induced and coexisting spin-triplet paired and magnetic states are considered within the doubly degenerate Hubbard model with interband hybridization. The Hartree-Fock approximation combined with the…
The standard Hartree--Fock approximation of the $O(N)-$invariant $\phi^4$ model suffers from serious renormalization problems. In addition, when the symmetry is spontaneously broken, another shortcoming appears in relation to the Goldstone…
Fractional-spin errors are inherent in all current approximate density functionals, including Hartree-Fock theory, and their origin has been related to strong static correlation effects. The conventional way to encode fractional-spin…
We apply Projected Hartree-Fock theory (PHF) for approximating ground states of Heisenberg spin clusters. Spin-rotational, point-group and complex-conjugation symmetry are variationally restored from a broken-symmetry mean-field reference,…
We develop a time-dependent Hartree-Fock approximation that is appropriate for Bose-condensed systems. Defining a {\it depletion Green's function} allows the construction of condensate and depletion particle densities from eigenstates of a…
The adaptive perturbation method decomposes a Hamiltonian by the diagonal elements and non-diagonal elements of the Fock state. The diagonal elements of the Fock state are solvable but can contain the information about coupling constants.…
Using the self-consistent Hartree-Fock approximation for spinless electrons at zero temperature, we study tunneling of the interacting electron gas through a single delta-barrier in a finite one-dimensional (1D) wire connected to contacts.…
The constraints imposed by asymptotic freedom and analyticity on the large-order behavior of perturbation theory for the electromagnetic current-current correlation function are examined. By suitably applying the renormalization group, the…