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Related papers: Dipolar needles in the microcanonical ensemble: ev…

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We study the magnetic structure of the ground state of an itinerant Fermi system of spin-\nicefrac{1}{2} particles with magnetic dipole-dipole interactions. We show that, quite generally, the spin state of particles depend on its momentum,…

Quantum Gases · Physics 2010-07-02 Benjamin M. Fregoso , Eduardo Fradkin

For the spherical model with nearest-neighbour interactions, the microcanonical entropy s(e,m) is computed analytically in the thermodynamic limit for all accessible values of the energy e and the magnetization m per spin. The entropy…

Statistical Mechanics · Physics 2009-12-11 Michael Kastner

We report here the results of micromagnetic simulations of square artificial spin ice (ASI) systems with defects. The defects are introduced by misaligning of a nanomagnet at the vertex. In these defective systems, we are able to stabilize…

Mesoscale and Nanoscale Physics · Physics 2019-12-10 Neeti Keswani , Pintu Das

We study the quantum phase transition occurring in an infinite homogeneous system of spin 1/2 fermions in a non-relativistic context. As an example we consider neutrons interacting through a simple spin-spin Heisenberg force. The two…

Nuclear Theory · Physics 2009-11-10 A. Beraudo , A. De Pace , M. Martini , A. Molinari

Using the low-energy effective field theory for magnons, we systematically evaluate the partition function of the O(3) ferromagnet up to three loops. Dyson, in his pioneering microscopic analysis of the Heisenberg model, showed that the…

Strongly Correlated Electrons · Physics 2013-05-29 Christoph P. Hofmann

We elucidate the itinerant ferromagnetism of a dipolar Fermi gas with a Raman-induced spin-orbit coupling by investigating the exotic phase diagrams at zero and finite temperature. It is revealed that the dipolar interaction along with…

Quantum Gases · Physics 2022-06-15 Xue-Jing Feng , Xing-Dong Zhao , Wu-Ming Liu

We analyze magnetic phases of monolayers of transition metal dichalcogenides that are two-valley materials with electron-electron interactions. The exchange inter-valley scattering makes two-valley systems less stable to the spin…

Strongly Correlated Electrons · Physics 2019-07-31 Dmitry Miserev , Jelena Klinovaja , Daniel Loss

We study the effect that randomness has on long-range interacting systems by using the ferromagnetic Ising model with $p$-body interactions in random fields. The case with p=2 yields a phase diagram similar to that of previously studied…

Disordered Systems and Neural Networks · Physics 2015-03-17 Zsolt Bertalan , Takehiro Kuma , Yoshiki Matsuda , Hidetoshi Nishimori

We present a simple two-dimensional model in which the lattice degrees of freedom mediate the interactions between magnetic moments and electric dipoles. This model reproduces basic features, such as a sudden electric polarization…

Strongly Correlated Electrons · Physics 2022-04-06 L. Pili , R. A. Borzi , D. C. Cabra , S. A. Grigera

By molecular dynamics simulation, we have investigated classical Heisenberg spins, which are arrayed on a finite simple cubic lattice and interact with each other only by the dipole-dipole interaction, and have found its peculiar it…

Statistical Mechanics · Physics 2007-05-23 Katsuyoshi Matsushita , Ryoko Sugano , Akiyoshi Kuroda , Yusuke Tomita , Hajime Takayama

We determine the effective dipolar interaction between single domain two-dimensional ferromagnetic particles (islands or dots), taking into account their finite size. The first correction term decays as 1/D^5, where D is the distance…

Materials Science · Physics 2007-05-23 Paolo Politi , Maria Gloria Pini

Each single domain nano-magnet acts as a magnetic dipole in addition it oscillates its magnetization about the easy axis and rotates coherently depending upon temperature and anisotropy. In an ensemble of nano-magnets, the relaxation time…

Mesoscale and Nanoscale Physics · Physics 2013-02-04 Nilangshu K. Das , P. Barat

In an artificial 3D percolation nano medium, the clusters filled by the Ising magnets give rise to a topologically nontrivial magnetic structure, leading to new features of the ferromagnetic phase transition without an external magnetic…

Statistical Mechanics · Physics 2010-09-27 Gennadiy Burlak

We observe a spontaneous parity breaking bifurcation to a ferromagnetic state in a spatially trapped exciton-polariton condensate. At a critical bifurcation density under nonresonant excitation, the whole condensate spontaneously magnetizes…

A cluster Monte Carlo method for systems of classical spins with purely dipolar couplings is presented. It is tested and applied for finite arrays of perpendicular Ising dipoles on the triangular lattice. This model is a modification with…

Statistical Mechanics · Physics 2009-11-07 Ulrich K. Roessler

We investigate the p-spin model with Gaussian-distributed random interactions in the microcanonical ensemble using the replica theory. For p=2, there are only second-order phase transitions and we recover the results of Sherrington and…

Statistical Mechanics · Physics 2014-09-08 Zsolt Bertalan , Hidethoshi Nishimori

We introduce and investigate a coarse-grained model for quasi one-dimensional ferrogels. In our description the magnetic particles are represented by hard spheres with a magnetic dipole moment in their centers. Harmonic springs connecting…

Soft Condensed Matter · Physics 2013-06-04 M. A. Annunziata , A. M. Menzel , H. Löwen

The experimental realization of time dependent ultracold lattice systems has paved the way towards the implementation of new Hubbard-like Hamiltonians. We show that in a one dimensional two components lattice dipolar Fermi gas the…

Quantum Gases · Physics 2017-12-08 S. Fazzini , A. Montorsi , M. Roncaglia , L. Barbiero

We investigate in detail the initial susceptibility, magnetization curves, and microstructure of ferrofluids in various concentration and particle dipole moment ranges by means of molecular dynamics simulations. We use the Ewald summation…

Soft Condensed Matter · Physics 2016-08-16 Zuowei Wang , Christian Holm , Hanns Walter Müller

A two-dimensional easy-plane ferromagnetic substrate, interacting with a dipolar tip which is magnetised perpendicular with respect to the easy plane is studied numerically by solving the Landau-Lifshitz Gilbert equation. Due to the…

Other Condensed Matter · Physics 2013-01-23 Martin P. Magiera , Alfred Hucht , Haye Hinrichsen , Silvio R. Dahmen , Dietrich E. Wolf