Essays about: "Hartree-Fock approximation"

Showing result 1 - 5 of 7 essays containing the words Hartree-Fock approximation.

1. 1. Near-local density approximation approach to one-dimensional lattice systems

   University essay from Lunds universitet/Matematisk fysik; Lunds universitet/Fysiska institutionen

   Author : Basheer Joudeh; [2018]
   Keywords : DFT; Hartree; Hartree-Fock; LDA; BALDA; Mean-field; Hubbard; SOFT; Physics and Astronomy;

   Abstract : Describing many-body quantum systems has been an analytically and computationally challenging task since the advent of quantum mechanics. However, in the past 50 years as a result of our technological advancement and the emergence of methods such as density-functional theory (DFT), we have taken crucial steps forward regarding our ability to study and understand large quantum systems. READ MORE

3. 2. A mean-field approach to attractive few-body Fermi gas

   University essay from Lunds universitet/Fysiska institutionen; Lunds universitet/Matematisk fysik

   Author : Morten Piibeleht; [2016]
   Keywords : HFB; hartree-fock-bogoliubov; fermi gas; higgs mode; QRPA; quasiparticles; random phase approximation; Physics and Astronomy;

   Abstract : Quantum many-body systems can be studied theoretically from first principles using microscopic models, but the computational cost of numerically exact calculations increases exponentially with the number of particles and the complexity of the interaction, limiting the systems that can be analysed. The Hartree-Fock-Bogoliubov (HFB) and quasiparticle random phase approximation (QRPA) methods, heavily used in nuclear physics, rely on mean-field approximations but scale more favourably with increasing system size and complexity. READ MORE

4. 3. Effects of electron-electron interaction in pristine and doped graphene

   University essay from Linnéuniversitetet/Institutionen för fysik och elektroteknik (IFE)

   Author : Faluke Aikebaier; [2014]
   Keywords : ;

   Abstract : The goal of this master thesis is to investigate the eect of electron-electron interaction on electronic properties of graphene that can be measured experimentally. A tight-binding model, which includes up to next-nearest-neighbor hopping, with parameters tted to density functional theory calculations, has been used to describe the electronic structure of graphene. READ MORE

5. 4. Exact Diagonalization of Few-electron Quantum Dots

   University essay from Institutionen för datavetenskap, fysik och matematik, DFM

   Author : Shirin Hakimi; [2009]
   Keywords : two-dimensional quantum dot; strongly correlated system; few-electron system; exact diagonalization; Lanczos method; Landau level; fractional quantum Hall effect; Wigner crystal; Hartree-Fock approximation; Second quantization;

   Abstract : We consider a system of few electrons trapped in a two-dimensional circularquantum dot with harmonic confinement and in the presence of ahomogeneous magnetic field, with focus on the role of e-e interaction. Byperforming the exact diagonalization of the Hamiltonian in second quantization,the low-lying energy levels for spin polarized system are obtained. READ MORE

6. 5. Elektronlokalisering och spinpolarisation i en kvantcirkel

   University essay from Institutionen för fysik, kemi och biologi

   Author : Erik Welander; [2009]
   Keywords : Spin polarization; electron localization;

   Abstract : Localization and magnetic properties of electrons in a thin, cyclic quasi one-dimensional GaAs wire with a central potential barrier were studied using the Hartree-Fock and LSDA (Local Spin Density Approximation, exchange only) and compared to more time consuming Quantum Monte-Carlo calculations. Within LSDA, evidence of true localization was found as well as evidence for the existence of both ferromagnetic as well as anti-ferromagnetic states. READ MORE