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Related papers: Symmetrizing the Constraints -- Density Matrix Ren…

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We have extended the density matrix renormalization group (DMRG) approach to two-fluid open many-fermion systems governed by complex-symmetric Hamiltonians. The applications are carried out for three- and four-nucleon (proton-neutron)…

Nuclear Theory · Physics 2009-01-22 J. Rotureau , N. Michel , W. Nazarewicz , M. Ploszajczak , J. Dukelsky

In these lecture notes, we present a pedagogical review of a number of related {\it numerically exact} approaches to quantum many-body problems. In particular, we focus on methods based on the exact diagonalization of the Hamiltonian matrix…

Strongly Correlated Electrons · Physics 2007-05-23 Reinhard M. Noack , Salvatore R. Manmana

In this study, we report a parallel algorithm for the infinite-size density matrix renormalization group (iDMRG) that is applicable to one-dimensional (1D) quantum systems with $\ell$-site periods, where $\ell$ is an even number. It…

Strongly Correlated Electrons · Physics 2018-07-03 Hiroshi Ueda

The density matrix renormalization group (DMRG) method has already proved itself as a very efficient and accurate computational method, which can treat large active spaces and capture the major part of strong correlation. Its application on…

Chemical Physics · Physics 2022-10-31 Pavel Beran , Katarzyna Pernal , Fabijan Pavosevic , Libor Veis

We apply a recent adaptation of White's density matrix renormalisation group (DMRG) method to a simple quantum spin model, the dimerised $XY$ chain, in order to assess the applicabilty of the DMRG to quantum systems at non-zero temperature.…

Condensed Matter · Physics 2009-10-28 R. J. Bursill , T. Xiang , G. A. Gehring

We introduce a Lagrangian formulation of the Density Matrix Renormalization Group (DMRG). We present Lagrangians which when minimised yield the optimal DMRG wavefunction in a variational sense, both within the general matrix product ansatz,…

Strongly Correlated Electrons · Physics 2008-04-11 Garnet Kin-Lic Chan

In the Density Matrix Renormalization Group (DMRG) algorithm, Hamiltonian symmetries play an important role. Using symmetries, the matrix representation of the Hamiltonian can be blocked. Diagonalizing each matrix block is more efficient…

Strongly Correlated Electrons · Physics 2012-06-29 G. Alvarez

Density matrix renormalization group (DMRG) is one of the most powerful numerical methods available for many-body systems. In this work, we develop a perturbation theory of DMRG (PT-DMRG) to largely increase its accuracy in an extremely…

Strongly Correlated Electrons · Physics 2017-03-01 Emanuele Tirrito , Shi-Ju Ran , Andrew J. Ferris , Ian P. McCulloch , Maciej Lewenstein

We investigate the density matrix renormalization group (DMRG) discovered by White and show that in the case where the renormalization eventually converges to a fixed point the DMRG ground state can be simply written as a ``matrix product''…

Condensed Matter · Physics 2009-10-28 Stefan Rommer , Stellan Ostlund

We have devised and implemented a local ab initio Density Matrix Renormalization Group (DMRG) algorithm to describe multireference nondynamic correlations in large systems. For long molecules that are extended in one of their spatial…

Strongly Correlated Electrons · Physics 2009-11-11 Johannes Hachmann , Wim Cardoen , Garnet Kin-Lic Chan

This thesis gives an extension for the Density Matrix Renormalisation Group (DMRG) to two dimensions and described a newly developed combination of the DMRG and a Green Function Monte Carlo simulation (GFMC). The first two chapters focus on…

Statistical Mechanics · Physics 2007-05-23 M. S. L. du Croo de Jongh

The density matrix renormalization group (DMRG) approach is extended to complex-symmetric density matrices characteristic of many-body open quantum systems. Within the continuum shell model, we investigate the interplay between many-body…

Nuclear Theory · Physics 2009-11-11 J. Rotureau , N. Michel , W. Nazarewicz , M. Ploszajczak , J. Dukelsky

Classical probability distributions on sets of sequences can be modeled using quantum states. Here, we do so with a quantum state that is pure and entangled. Because it is entangled, the reduced densities that describe subsystems also carry…

Quantum Physics · Physics 2020-12-10 Tai-Danae Bradley , E. Miles Stoudenmire , John Terilla

Shared-memory parallelization (SMP) strategies for density matrix renormalization group (DMRG) algorithms enable the treatment of complex systems in solid state physics. We present two different approaches by which parallelization of the…

Strongly Correlated Electrons · Physics 2009-11-10 G. Hager , E. Jeckelmann , H. Fehske , G. Wellein

The density matrix renormalization group (DMRG) method introduced by White for the study of strongly interacting electron systems is reviewed; the method is variational and considers a system of localized electrons as the union of two…

Strongly Correlated Electrons · Physics 2009-10-31 G. Fano , F. Ortolani , L. Ziosi

In a recent Letter [Phys. Rev. Lett. 88, 256403(2002), cond-mat/0109158] Cazalilla and Marston proposed a time-dependent density- matrix renormalization group (TdDMRG) algorithm for the accurate evaluation of out-of-equilibrium properties…

Strongly Correlated Electrons · Physics 2007-05-23 H. G. Luo , T. Xiang , X. Q. Wang

In this work, we simulate the electron dynamics in molecular systems with the Time-Dependent Density Matrix Renormalization Group (TD-DMRG) algorithm. We leverage the generality of the so-called tangent-space TD-DMRG formulation and design…

Chemical Physics · Physics 2021-06-08 Alberto Baiardi

We develop a renormalization group (RG) description of the localization properties of onedimensional (1D) quasiperiodic lattice models. The RG flow is induced by increasing the unit cell of subsequent commensurate approximants. Phases of…

Disordered Systems and Neural Networks · Physics 2023-10-10 Miguel Gonçalves , Bruno Amorim , Eduardo V. Castro , Pedro Ribeiro

The Density Matrix Renormalization Group (DMRG) method scales exponentially in the system width for models in two dimensions, but remains one of the most powerful methods for studying 2D systems with a sign problem. Reviewing past…

Strongly Correlated Electrons · Physics 2012-03-15 E. M. Stoudenmire , Steven R. White

In this paper we describe how the density matrix renormalization group (DMRG) can be used for quantum chemical calculations for molecules, as an alternative to traditional methods, such as configuration interaction or coupled cluster…

Condensed Matter · Physics 2009-10-31 Steven R. White , Richard L. Martin