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Related papers: Shifted COCG method and its application to double …

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The modification of the magnetization dissipation or Gilbert damping caused by an inhomogeneous magnetic structure and expressed in terms of a wave vector dependent tensor $\underline{\alpha}(\vec{q})$ is investigated by means of linear…

Materials Science · Physics 2018-09-12 S. Mankovsky , S. Wimmer , H. Ebert

The study of ground-state properties of the Fermi-Hubbard model is a long-lasting task in the research of strongly correlated systems. Owing to the exponentially growing complexity of the system, a quantitative analysis usually demands high…

Strongly Correlated Electrons · Physics 2023-08-15 Yue-Ran Shi , Yuan-Yao He , Ruijin Liu , Wei Zhang

In the present study, we establish two new block variants of the Conjugate Orthogonal Conjugate Gradient (COCG) and the Conjugate A-Orthogonal Conjugate Residual (COCR) Krylov subspace methods for solving complex symmetric linear systems…

Numerical Analysis · Mathematics 2016-01-21 Xian-Ming Gu , Bruno Carpentieri , Ting-Zhu Huang , Jing Meng

We propose the reduced-shifted Conjugate-Gradient (RSCG) method, which is numerically efficient to calculate a matrix element of a Green's function defined as a resolvent of a Hamiltonian operator, by solving linear equations with a desired…

Superconductivity · Physics 2017-02-01 Yuki Nagai , Yasushi Shinohara , Yasunori Futamura , Tetsuya Sakurai

On the basis of spin and pairing fluctuation-exchange approximation, we study the superconductivity in quasi-two-dimensional Hubbard model. The integral equations for the Green's function are self-consistently solved by numerical…

Superconductivity · Physics 2009-10-23 Xin-Zhong Yan

We develop a nonequilibrium multi-orbital extension of the two-particle self-consistent theory and apply it to the bilayer Hubbard model as a minimal platform to investigate correlation effects in the presence of interlayer interactions and…

Strongly Correlated Electrons · Physics 2025-10-16 Jiawei Yan , Jonas B. Profe , Yuta Murakami , Philipp Werner

Precise predictions of atomic energy levels require the use of QED, especially in highly-charged ions, where the inner electrons have relativistic velocities. We present an overview of the two-time Green's function method; this method…

Atomic Physics · Physics 2007-05-23 E. -O. Le Bigot , P. Indelicato , V. M. Shabaev

The famous, yet unsolved, Fermi-Hubbard model for strongly-correlated electronic systems is a prominent target for quantum computers. However, accurately representing the Fermi-Hubbard ground state for large instances may be beyond the…

Using the strong coupling diagram technique equations are derived for hole Green's functions of the three-band Hubbard model, which describes Cu-O planes of high-$T_c$ cuprates. The equations are self-consistently solved in the…

Strongly Correlated Electrons · Physics 2019-05-21 A. Sherman

We demonstrate that at a filling of $n=1.5$, an hexatic insulating state obtains in the extended Hubbard model on a triangular lattice. Composed of two tetragonal sublattices with fillings of $n=1$ and $n=2$, the insulating state is charge…

Strongly Correlated Electrons · Physics 2013-05-29 Ting-Pong Choy , Dimitrios Galanakis , Philip Phillips

A new mathematical model for the description of three electron quantum dots in 2D space is created, and ground states of this system in external magnetic field is investigated. The Schrodinger equation for three two-dimensional electrons is…

Mathematical Physics · Physics 2007-10-20 Lia Leon Margolin , Shalva Tsiklauri

Quasicrystals are long-range ordered, yet not periodic, and thereby present a fascinating challenge for condensed matter physics, as one cannot resort to the usual toolbox based on Bloch's theorem. Here, we present a numerical method for…

Disordered Systems and Neural Networks · Physics 2023-04-18 Emmanuel Gottlob , Ulrich Schneider

We introduce a systematic low-energy approach to strongly correlated electron systems in infinite dimensions, and apply it to the problem of the correlation-induced metal-insulator transition in the half-filled Hubbard model. We determine…

Condensed Matter · Physics 2007-05-23 Goetz Moeller , Qimiao Si , Gabriel Kotliar , Marcelo Rozenberg

The self-consistent theory of the correlation effects in Highly Correlated Systems(HCS) is presented. The novel Irreducible Green's Functions(IGF) method is discused in detail for the Hubbard model and random Hubbard model. The…

Strongly Correlated Electrons · Physics 2008-02-03 A. L. Kuzemsky

In this paper, we present a quantum computational method to calculate the many-body Green's function matrix in a spin orbital basis. We apply our approach to finite-sized fermionic Hubbard models and related impurity models within Dynamical…

Many problems in science and engineering fields require the solution of shifted linear systems. To solve such systems efficiently, the recycling BiCG (RBiCG) algorithm in [SIAM J. SCI. COMPUT, 34 (2012) 1925-1949] is extended in this paper.…

Numerical Analysis · Mathematics 2014-06-26 Jing Meng , Pei-yong Zhu , Hou-Biao Li

Numerical results for ground state and excited state properties (energies, double occupancies, and Matsubara-axis self energies) of the single-orbital Hubbard model on a two-dimensional square lattice are presented, in order to provide an…

The method of McCurdy, Baertschy, and Rescigno, J. Phys. B, 37, R137 (2004) is generalized to obtain a straightforward, surprisingly accurate, and scalable numerical representation for calculating the electronic wave functions of molecules.…

A method to calculate the one-body Green's function for ground states of correlated electron materials is formulated by extending the variational Monte Carlo method. We benchmark against the exact diagonalization (ED) for the one- and…

Strongly Correlated Electrons · Physics 2020-11-11 Maxime Charlebois , Masatoshi Imada

This study is mainly focused on iterative solutions to shifted linear systems arising from a Quantum Chromodynamics (QCD) problem. To solve such system efficiently, we explore a kind of shifted QMRCGstab (SQMRCGstab) methods, which is…

Numerical Analysis · Mathematics 2013-05-27 Jing Meng , Pei-yong Zhu , Hou-Biao Li