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Showing 1 to 20 of 29 for “"Variational Monte Carlo"”.
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Variational Monte Carlo estimation of the dissociation energy of CuH using correlated sampling
… approach to treating large Z systems by quantum Monte Carlo has been developed. It naturally leads to notion of the 'valence energy'. Possibilities of the new approach has been explored by optimizing the wave function for CuH and Cu and computing dissociation energy and dipole moment of CuH using …
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COMBINING QUANTUM TRAJECTORIES AND TIME-DEPENDENT VARIATIONAL MONTE CARLO FOR MANY-BODY OPEN QUANTUM SYSTEMS
… systems. This thesis introduces the Open-Time Variational Monte Carlo (otVMC) method, which combines the quantum trajectory formalism with Monte Carlo tech- niques to enable real-time simulations of open quantum systems. By exploiting stochas- tic Schrödinger equations and a variational …
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Variational Monte Carlo study of core-valence separation schemes for first-row atoms and positive ions /
… overlap. These effects are studied with the variational Monte Carlo method using appropriately designed wave functions for the first-row atoms and positive ions. It is shown that the loss of antisymmetry with respect to interchange of core and valence electrons is a dominant effect which …
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Pairing and entanglement: quantum Monte Carlo studies
… in this dissertation is the use of quantum Monte Carlo methods to study two ideas in quantum many-body problems: superfluidity and entanglement. Density matrices are presented a central tool in the analysis, as are discussed in the review of path integral Monte Carlo (PIMC) and variational …
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Quantum Monte Carlo With a *Stochastic Poisson Solver
"Quantum Monte Carlo (QMC) is an extremely powerful method to treat many-body systems. Usually QMC has been applied in cases where the interaction potential has a simple analytic form, like the 1/r Coulomb potential. However, in a complicated environment as in a semiconductor heterostructure, the …
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Quantum monte carlo with a stochastic potential solver
"Quantum Monte Carlo (QMC) is an extremely powerful method to treat many-body systems. Usually QMC has been applied in cases where the interaction potential has a simple analytic form, like the 1=r Coulomb potential. However, in a complicated environment as in a semiconductor heterostructure, the …
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Lie algebraic similarity transformations: improving wavefunctions for weak and strong correlations
… of this form have been studied with variational Monte Carlo methods, but we present a formalism to perform non-stochastic calculations. The Hausdorff series generated by these Jastrow factors can be summed exactly without truncation resulting in a set of equations with polynomial …
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Variational study of strongly correlated electronic models
… and t−J models. Motivated by the success of variational Monte- Carlo to describe some of the peculiar properties of the cuprates, we propose in this dissertation, on one hand, to extend the method to further strongly corre- lated models to describe other compounds such as graphene, carbon …
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Tunable Exchange Interaction in Coupled Quantum Dots
… dot (QD) systems are investigated by using the variational Monte Carlo (VMC) method in the presence of magnetic fields. For N = 2 electrons in double QD, the singlet Coulomb energy decreases in magnetic fields as a consequence of magnetic localization in both strongly and weakly coupled QDs. …
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Quantum Monte Carlo Calucations Of Three And Six-Quark States
Quantum Monte Carlo techniques are applied to quark descriptions of single baryon and nuclear systems using a non-relativistic constituent quark model Hamiltonian. The assumed interaction includes a three-body term arising due to flux-tube confinement, and two-body interactions arising from …
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Relativistic Hamiltonians and short range structure of nuclei
… potentials and their boost corrections. Variational Monte Carlo method is used to study two kinds of relativistic effects in the binding energy of 3H and 4He. The first is due to the nonlocalities in the relativistic kinetic energy and relativistic one-pion exchange potential (OPEP), and …
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Quantum Monte Carlo: Applications of the Twist -Averaged Boundary Conditions and the Calculation of Forces
Quantum Monte Carlo (QMC) method is a powerful simulation tool for studying the properties of physical and chemical systems. The application of QMC to extended systems subjects to finite size effects because the simulation is often done with a small system in a super cell geometry. Periodic …
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Relativistic Hamiltonians and Short-Range Structure of Nuclei
… potentials and their boost corrections. Variational Monte Carlo method is used to study two kinds of relativistic effects in the binding energy of $\sp3$H and $\sp4$He. The first is due to the nonlocalities in the relativistic kinetic energy and relativistic one-pion exchange potential …
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Spin Polarization of Ground State Electron Gas at Low Densities
… of materials. In this work we use Quantum Monte Carlo simulations to study the spontaneous polarization of electron gas at low densities, for both two and three dimensions. Quantum Monte Carlo is a powerful method to tackle many-body Fermion problems, and its high accuracy has been …
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Quantum Monte Carlo: Applications of the Twist-averaged Boundary Conditions and the Calculation of Forces
Quantum Monte Carlo(QMC) method is a powerful simulation tool for studying the properties of physical and chemical systems. The application of QMC to extended systems subjects to finite size effects because the simulation is often done with a small system in a super cell geometry. Periodic boundary …
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A quantum Monte Carlo study of the two-dimensional electron gas
Quantum Monte Carlo has recently made great progress as a computational tool for quantum many-body systems. We have extended previous Monte Carlo methods to study both ground state and excited states of the two-dimensional electron gas. For ground state properties we have used variational and …
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Backflow and pairing wave function for quantum Monte Carlo methods
Quantum Monte Carlo (QMC) methods are a class of stochastic techniques that can be used to compute the properties of electronic systems accurately from first principles. This thesis is mainly concerned with the development of trial wave functions for QMC. An extension of the backflow transformation …
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Transport properties in the vicinity of Mott insulators
… coupling limit, i.e. the t-J model. Using the variational Monte Carlo technique, we study Gutzwiller projected states. In particular, studying the projected BCS quasiparticles, we calculate the renormalization of the quasipaticle current and the spectral weight. Both are investigated as a …
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Monte Carlo methods: application to hydrogen gas and hard spheres
Quantum Monte Carlo (QMC) methods are among the most accurate for computing ground state properties of quantum systems. The two major types of QMC we use are Variational Monte Carlo (VMC), which evaluates integrals arising from the variational principle, and Diffusion Monte Carlo (DMC), which …
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Aspects of critical spin 1 chains and 2 dimensional symmetry protected topological phases of matter
… brief description of a potential application of variational Monte Carlo to spin-orbit coupled ab initio systems.
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