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Related papers: Conjugate gradient methods in micromagnetics

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In this paper, based on the limited memory techniques and subspace minimization conjugate gradient (SMCG) methods, a regularized limited memory subspace minimization conjugate gradient method is proposed, which contains two types of…

Optimization and Control · Mathematics 2023-01-10 Wumei Sun , Hongwei Liu , Zexian Liu

We present the open source micromagnetic framework, MagTense, which utilizes a novel discretization approach of rectangular cuboid or tetrahedron geometry "tiles" to analytically calculate the demagnetization field. Each tile is assumed to…

Computational Physics · Physics 2021-07-13 R. Bjørk , E. B. Poulsen , K. K. Nielsen , A. R. Insinga

The efficient solution of large-scale multiterm linear matrix equations is a challenging task in numerical linear algebra, and it is a largely open problem. We propose a new iterative scheme for symmetric and positive definite operators,…

Numerical Analysis · Mathematics 2025-05-27 Davide Palitta , Martina Iannacito , Valeria Simoncini

The magnetic properties of dilute magnetic semiconductors (DMS) are calculated from first-principles by mapping the ab initio results on a classical Heisenberg model. It is found that the range of the exchange interaction in (Ga, Mn)N is…

Materials Science · Physics 2007-05-23 K. Sato , W. Schweika , P. H. Dederichs , H. Katayama-Yoshida

We formulated a technique which combines the first-principles, micromagnetic and microstructural calculations and allows us to study the nature of hysteretic phenomena in hard magnets. Two distinct sources of coercivity in polytwinned CoPt…

Materials Science · Physics 2009-11-07 K. D. Belashchenko , V. P. Antropov

The magnetocaloric effect or "magnetic Gr\"uneisen ratio" $\Gamma_H=T^{-1}(dT/dH)_S$ quantifies the cooling or heating of a material when an applied magnetic field is changed under adiabatic conditions. Recently this property has attracted…

Strongly Correlated Electrons · Physics 2013-06-25 Yoshi Tokiwa , Philipp Gegenwart

The Conjugate Gradient method (CGM) is known to be the fastest generic iterative method for solving linear systems with symmetric sign definite matrices. In this paper, we modify this method so that it could find fundamental solitary waves…

Pattern Formation and Solitons · Physics 2015-05-13 Taras I. Lakoba

We consider the numerical approximation of a continuum model of antiferromagnetic and ferrimagnetic materials. The state of the material is described in terms of two unit-length vector fields, which can be interpreted as the magnetizations…

Numerical Analysis · Mathematics 2023-12-11 Hywel Normington , Michele Ruggeri

(Mini-batch) Stochastic Gradient Descent is a popular optimization method which has been applied to many machine learning applications. But a rather high variance introduced by the stochastic gradient in each step may slow down the…

Machine Learning · Computer Science 2018-10-09 Jingchang Liu , Linli Xu

Stellarators are a promising route to steady-state fusion power. However, to achieve the required confinement, the magnetic geometry must be highly optimized. This optimization requires navigating high-dimensional spaces, often…

Plasma Physics · Physics 2019-09-25 Elizabeth Paul , Ian Abel , Matt Landreman , William Dorland

We systematically investigate the magnetophoresis of weakly paramagnetic manganese oxide nanoparticles under nonuniform magnetic fields using a combination of experiments and multiphysics numerical simulations. Experiments were conducted in…

Materials Science · Physics 2025-06-06 Peter Rassolov , Jamel Ali , Theo Siegrist , Munir Humayun , Hadi Mohammadigoushki

In a recent paper (J. Chem. Theory. Comput., 2017, 13, 180-190) we proposed the Truncated Conjugate Gradient (TCG) approach to compute the polarization energy and forces in polarizable molecular simulations. The method consists in…

Chemical Physics · Physics 2017-09-05 Félix Aviat , Louis Lagardère , Jean-Philip Piquemal

Due to its optimal complexity, the multigrid (MG) method is one of the most popular approaches for solving large-scale linear systems arising from the discretization of partial differential equations. However, the parallel implementation of…

Numerical Analysis · Mathematics 2025-02-27 Hardik Kothari , Maria Giuseppina Chiara Nestola , Marco Favino , Rolf Krause

A stochastic conjugate gradient method for approximation of a function is proposed. The proposed method avoids computing and storing the covariance matrix in the normal equations for the least squares solution. In addition, the method…

Numerical Analysis · Mathematics 2013-02-11 Hong Jiang , Paul Wilford

When the gate set has continuous parameters, synthesizing a unitary operator as a quantum circuit is always possible using exact methods, but finding minimal circuits efficiently remains a challenging problem. The landscape is very…

Quantum Physics · Physics 2026-01-07 Janani Gomathi , Alex Meiburg

We extend a renormalization group-based course-graining method for micromagnetic simulations to include properly scaled magnetostatic interactions. We apply the method in simulations of dynamic hysteresis loops at clinically relevant sweep…

Mesoscale and Nanoscale Physics · Physics 2021-05-26 Razyeh Behbahani , Martin L. Plumer , Ivan Saika-Voivod

Decoherence processes in crystals of molecular magnets are prototypical for interacting electronic spin systems. We analyze the Landau-Zener dynamics of the archetypical TbPc$_2$ complex diluted in a diamagnetic monocrystal. The dependence…

Mesoscale and Nanoscale Physics · Physics 2020-04-21 Gheorghe Taran , Edgar Bonet , Wolfgang Wernsdorfer

We present an iterative method to diagonalise large matrices. The basic idea is the same as the conjugated gradient (CG) method, i.e, minimizing the Rayleigh quotient via its gradient and avoiding reintroduce errors to the directions of…

Computational Physics · Physics 2009-11-10 Quanlin Jie , Dunhuan Liu

The numerical solution of algebraic tensor equations is a largely open and challenging task. Assuming that the operator is symmetric and positive definite, we propose two new gradient-descent type methods for tensor equations that…

Numerical Analysis · Mathematics 2026-02-26 Martina Iannacito , Lorenzo Piccinini , Valeria Simoncini

Connections of the conjugate gradient (CG) method with other methods in computational mathematics are surveyed, including the connections with the conjugate direction method, the subspace optimization method and the quasi-Newton method BFGS…

Numerical Analysis · Mathematics 2019-12-17 Xuping Zhang , Jiefei Yang , Ziying Liu