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Related papers: Dipolar ordering of random two-dimensional spin en…

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We study a family of models for an $N_1 \times N_2$ matrix worth of Ising spins $S_{aB}$. In the large $N_i$ limit we show that the spins soften, so that the partition function is described by a bosonic matrix integral with a single…

High Energy Physics - Theory · Physics 2019-12-25 Sean A. Hartnoll , Edward A. Mazenc , Zhengyan D. Shi

Binary random compacts with different proportions of small (volume V) and large (volume 2V) bare maghemite nanoparticles (NPs) are used to investigate the effect of controllably broadening the particle size distribution on the magnetic…

Self-assembly of particles with short-range attraction and long-range repulsion (SALR) interactions on a flat and on a spherical surface is compared. Molecular dynamics (MD) simulations are performed for the two systems having the same area…

Soft Condensed Matter · Physics 2018-11-20 Jakub Pękalski , Alina Ciach

We report an experimental study of 2D dipole clusters formed by small magnetic particles floating at the air-water interface. The particles form hexagonally ordered clusters due to interplay between dipole-dipole repulsion and confining…

Soft Condensed Matter · Physics 2007-05-23 M. Golosovsky , Y. Saado , D. Davidov

The magnetically frustrated spin ice family of materials is host to numerous exotic phenomena such as magnetic monopole excitations and macroscopic residual entropy extending to low temperature. A finite-temperature ordering transition in…

The disordered random-anisotropy magnetic nanoparticle systems with competing dipolar interactions and ferromagnetic exchange couplings are investigated by Monte Carlo simulations. Superspin glass (SSG) and superferromagnetic (SFM)…

Disordered Systems and Neural Networks · Physics 2015-05-27 Zhongquan Mao , Xi Chen

Spin-polarons are obtained using an Ising-like exchange model consisting of double and super-exchange interactions in low dimensional systems. At zero temperature, a new phase separation between small magnetic polarons, one conduction…

Strongly Correlated Electrons · Physics 2015-06-18 O. Navarro , E. Vallejo , M. Avignon

Recently it has been suggested that long range magnetic dipolar interactions are responsible for spin ice behavior in the Ising pyrochlore magnets ${\rm Dy_{2}Ti_{2}O_{7}}$ and ${\rm Ho_{2}Ti_{2}O_{7}}$. We report here numerical results on…

Disordered Systems and Neural Networks · Physics 2009-10-31 Roger G. Melko , Byron C. den Hertog , Michel J. P. Gingras

The level statistics in the two dimensional disordered electron systems in magnetic fields (unitary ensemble) or in the presence of strong spin-orbit scattering (symplectic ensemble) are investigated at the Anderson transition points. The…

Condensed Matter · Physics 2009-10-28 Tomi Ohtsuki , Yoshiyuki Ono

The thermally activated magnetic relaxation in two-dimensional ensembles of dipolar interacting nanoparticles with large uniaxial perpendicular anisotropy is studied by a numerical method and within the mean-field approximation. The role…

Condensed Matter · Physics 2009-11-10 S. I. Denisov , T. V. Lyutyy , K. N. Trohidou

We propose a general protocol for on-demand generation of robust entangled states of nuclear and/or electron spins of ultracold $^1\Sigma$ and $^2\Sigma$ polar molecules using electric dipolar interactions. By encoding a spin-1/2 degree of…

Quantum Physics · Physics 2023-04-10 Timur V. Tscherbul , Jun Ye , Ana Maria Rey

We revisit the one-dimensional ferromagnetic Ising spin-chain with a finite number of spins and periodic boundaries and derive analytically and verify numerically its various stationary and dynamical properties at different temperatures. In…

Statistical Mechanics · Physics 2025-04-24 Varazdat Stepanyan , Andreas F. Tzortzakakis , David Petrosyan , Armen E. Allahverdyan

A model for a monolayer of two types of particles spontaneously forming ordered patterns is studied by a mesoscopic theory and by MC simulations. We assume hard-cores of the same size for both components, short-range attraction long-range…

Soft Condensed Matter · Physics 2023-11-10 O. Patsahan , A. Meyra , A. Ciach

Dipolar coupling in crystals of the Mn$_{12}$Ac molecular magnet elongated along the anisotropy axis favors ferromagnetic ordering below the mean-field Curie temperature 0.71 K. With the help of Monte Carlo on crystals of up to one million…

Statistical Mechanics · Physics 2016-11-16 D. A. Garanin

Entanglement and quantum discord for a pair of nuclear spins $s=1/2$ in a nanopore filled with a gas of spin-carrying molecules (atoms) are studied. The correlation functions describing dynamics of dipolar coupled spins in a nanopore are…

Quantum Physics · Physics 2012-11-12 E. B. Fel'dman , E. I. Kuznetsova , M. A. Yurishchev

Spin-crossover compounds, which are characterized by magnetic ions showing low-spin and high-spin states at thermally accessible energies, are ubiquitous in nature. We here focus on the effect of an exchange interaction on the collective…

Statistical Mechanics · Physics 2009-11-13 Carsten Timm , Charles J. Pye

The magnetic susceptibility and spin-spin correlation of the double-exchange model for doped manganites are investigated through the Monte Carlo calculations on the three-dimensional lattice model. Deviations of the susceptibility from the…

Strongly Correlated Electrons · Physics 2009-10-31 Hongsuk Yi , N. H. Hur , Jaejun Yu

Nuclear spins' dipolar order is created under magic angle spinning through the first-order process made possible by simultaneous implementation of dipolar recoupling and adiabatic demagnetization in a reference frame reached out through…

Quantum Physics · Physics 2025-06-30 Kohei Suzuki , Kazuyuki Takeda

We combine the anisotropy of magnetic interactions and the point symmetry of finite solids in the study of dipolar clusters as new basic units for multiferroics metamaterials. The hamiltonian of magnetic dipoles with an easy axis at the…

Materials Science · Physics 2020-12-03 Paula Mellado , Andres Concha , Sergio Rica

We use soft x-ray vector-ptychographic tomography to determine the three-dimensional magnetization field in superparamagnetic nanoparticles self-assembled at the liquid-liquid interface and reveal the magnetic order induced by layered…