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Showing 1 to 17 of 17 for “"density matrix renormalization group"”.
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Applications of the density matrix renormalization group to mesoscopic phenomena
… To this purpose, I adapt and use the density-matrix renormalization group (DMRG), a numerical method that has been developed specifically for analyzing such systems. The following systems are discussed: - Josephson effect between superconducting nanograins: I investigate the Josephson …
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The adaptive time-dependent density matrix renormalization group method : development and applications
… numerical method, the adaptive time-dependent density-matrix renormalization-group (adaptive t-DMRG), which turns out to be very well suited to investigate time-dependent phenomena in one-dimensional strongly correlated systems. The method is based on the original density-matrix renormalization …
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Density Matrix Renormalization Group Studies of Strongly Correlated Systems in Low Dimensions
The density matrix renormalization group method (DMRG) is a powerful numerical method for strongly correlated systems, which often cannot be solved analytically either by the mean field approach or through perturbation. The DMRG is originally proposed as an iterative search of the ground state in …
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Simulating quantum systems on classical computers with matrix product states
… many-body quantum-mechanical systems using matrix product states (MPS) is considered. Compared to classical systems, quantum many-body systems possess an exponentially enlarged number of degrees of freedom, significantly complicating a simulation on a classical computer. …
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Implementing a Lattice Formulation of the Schwinger Modelwith Periodic Boundary Conditions Using Tensor Networks
… with the local optimization steps used in the density matrix renormalization group (DMRG) algorithm for finding the ground state of a quantum system. However, due to practical constraints, I still use matrix product states and matrix product operators with open boundary conditions. I …
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Grundzustandseigenschaften von anisotropen antiferromagnetischen Heisenberg-Ketten mit Spin S = 1
… anisotropy. The method primarily employed is the density matrix renormalization group (DMRG) for a finite chain length and in the thermodynamic limit (iDMRG). The phase diagrams of the quantum spin chain and the corresponding classical model are compared for the first time. Thereby the similarity …
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Advances in Multiconfiguration Pair Density Functional Theory and Applications to Excited State, Singlet-Triplet Gaps and Magnetism
… method called multiconfiguration pair-density functional theory (MC-PDFT), developed by Gagliardi and Truhlar groups, can be used to accurately account for electron correlation effects in multireference systems. The advantage of MC- PDFT is that it can accurately describe molecular …
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Numerical and Analytical Methods in Low-Dimensional Strongly Correlated Quantum Systems
… from a 1D Luttinger liquid to a charge density wave insulator, characterized by partly Kosterlitz-Thouless transition and partly Ising transition, is analyzed using both analytical renormalization group calculations and numerical density matrix renormalization group simulations. …
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On the Phase Diagram of the Heisenberg Gamma Ladder
… a phase diagram of the system using the Infinite Density Matrix Renormalization Group (iDMRG) numerical technique. In order to classify the phases, we search for discontinuities in the entanglement spectrum for bonds along one of the legs and the rungs of the ladder while also looking at …
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Dynamics of quantum many-body systems with long-range interactions
… method of quantum state estimation, certified Matrix Product State (MPS) tomography, which has potential applications in regimes unreachable by full quantum state tomography. The investigation of quantum many-body systems often goes beyond analytically solvable models; that is where numerical …
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Ferrimagnetos quase-unidimensionais frustrados
… da Matriz Densidade (DMRG, do inglês Density Matrix Renormalization Group). A cadeia AB2 (J =0) exibe estado fundamental ferrimagnético com magnetização m= 1 2 por célula unitária, como previsto pelo teorema de Lieb-Mattis. Para J=0, a fase ferrimagnética persiste até J= Jc1=0,35, …
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Aspects of critical spin 1 chains and 2 dimensional symmetry protected topological phases of matter
… using exact diagonalization (ED) and the density matrix renormalization group (DMRG) algorithm. In particular, the bosonization method gives a formula for the evolution of four Tomonaga-Luttinger liquid (TLL) parameters as a function of the lattice parameters. Using the analytic formulae …
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Numerical methods of characterizing symmetry protected topological states in one dimension
… topological (SPT) phases. We focus on the density matrix renormalization group (DMRG) methods and explore the machine learning methods. We investigated different SPT phases in the context of interactions and disorders. The application of machine learning methods reveals new insights into …
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Universal properties of the entanglement entropy in quantum integrable models
… of Levi [2012]. In the fifth and last chapter we group the most common methods used to study the entanglement entropy of quantum spin chains. We start with the XY chain analysis, which is performed with a combination of analytical and numerical methods based on free fermion techniques. We then …
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Finite and infinite matrix product states for Gutzwiller projected mean-field wavefunctions and their applications to quantum spin systems
… quantum spin systems. We further briefly discuss matrix product states as efficient representations of gapped quantum wavefunctions which are intimately related to the entanglement properties of these wavefunctions. We also present known results concerning the detection of exotic quantum orders …
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Entanglement entropy in quantum many particle systems and their simulation via ansatz states
… lattice models. For one-dimensional systems, the density-matrix renormalization-group (DMRG) is such a very successful method. The physical states of interest are approximated within a certain class of ansatz states. These ansatz states are designed in a way that the number of degrees of freedom …