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Related papers: Quantum Dynamics of a Nanomagnet driven by Spin-Po…

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We present a microscopic theory for the phonon-driven decay of the magnetization fluctuations in a wide class of nanomagnets where the dominant energy is set by isotropic exchange and/or uniaxial anisotropy. Based on the Zwanzig-Mori…

Mesoscale and Nanoscale Physics · Physics 2008-03-28 Ioannis Rousochatzakis

This paper shows that the presence of two dynamical regimes, characterized by different precessional-axis, is the origin of the non-monotonic behavior of the output integrated power for large-amplitude magnetization precession driven by…

Other Condensed Matter · Physics 2009-11-13 G. Siracusano , G. Finocchio , A. La Corte , G. Consolo , L. Torres , B. Azzerboni

Measurements of magnetic hysteresis loops in single Co nanoparticles at dilution refrigerator temperatures are presented. The nanoparticles are in electric contact with bulk Al leads via tunnel junctions. The tunnel current versus magnetic…

Mesoscale and Nanoscale Physics · Physics 2012-07-10 F. Tijiwa Birk , W. Jiang , D. Davidović

Spin-polarized current effect is studied on the static and dynamic magnetization of the antiferromagnet in a ferromagnet - antiferromagnet nanojunction. The macrospin approximation is generalized to antiferromagnets. Canted…

Materials Science · Physics 2011-12-13 E. M. Epshtein , Yu. V. Gulyaev , P. E. Zilberman

We investigate the magnetization dynamics of ferromagnetic nanoparticles in the atomistic approach taking account of surface anisotropy and the spin misalignment it causes. We demonstrate that such inhomogeneous spin configurations induce…

Mesoscale and Nanoscale Physics · Physics 2018-11-12 Roland Bastardis , Francois Vernay , Hamid Kachkachi

We propose a quantum processor based upon single-molecule magnets and spin transfer torque described by PT-symmetric quantum mechanics. In recent years PT-symmetric Hamiltonians have been used to obtain stability thresholds of various…

Mesoscale and Nanoscale Physics · Physics 2019-05-22 Aleix Bou Comas , Eugene M. Chudnovsky , Javier Tejada

In the presence of spatial variation of the magnetization direction, electric current noise causes a fluctuating spin-transfer torque that increases the fluctuations of the ferromagnetic order parameter. By the fluctuation-dissipation…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Jorn Foros , Arne Brataas , Yaroslav Tserkovnyak , Gerrit E. W. Bauer

We develop a theory for spin transport and magnetization dynamics in a quantum-dot spin valve, i.e., two magnetic reservoirs coupled to a quantum dot. Our theory is able to take into account effects of strong correlations. We demonstrate…

Mesoscale and Nanoscale Physics · Physics 2018-01-09 N. M. Gergs , S. A. Bender , R. A. Duine , D. Schuricht

We investigate the role of equilibrium and nonequilibrium noise in the magnetization dynamics on mono-domain ferromagnets. Starting from a microscopic model we present a detailed derivation of the spin shot noise correlator. We investigate…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 J. Swiebodzinski , A. Chudnovskiy , T. Dunn , A. Kamenev

Using a combination of semiclassical and recently developed wave packet propagation techniques we find the quantum self-ionization process of highly excited ions moving in magnetic fields which has its origin in the energy transfer from the…

Atomic Physics · Physics 2009-11-06 Vladimir Melezhik , Peter Schmelcher

We develop a quantum analog of the classical spin-torque model for current-driven magnetic dynamics. The current-driven magnetic excitation at finite field becomes significantly incoherent. This excitation is described by an effective…

Materials Science · Physics 2009-11-10 S. Urazhdin

The quantum mechanical states of the neutral particle endowed with a magnetic moment in the combination of electromagnetic vortex field together with the constant magnetic field are dealt with. It is shown that this system of fields is…

Quantum Physics · Physics 2018-08-08 Tomasz Radożycki

We consider bosons in a Hubbard lattice with an SU($\cal N$) pseudospin degree of freedom which is made dynamical via a coherent transfer term. It is shown that, in the basis which diagonalizes the pseudospin coupling, a generic hopping…

Quantum Gases · Physics 2014-11-19 Tobias Graß , Alessio Celi , Maciej Lewenstein

We investigate numerically the magnetisation dynamics of an array of nano-disks interacting through the magneto-dipolar coupling. In the presence of a temperature gradient, the chain reaches a non-equilibrium steady state where energy and…

Statistical Mechanics · Physics 2015-03-03 Simone Borlenghi , Stefano Iubini , Stefano Lepri , Jonathan Chico , Lars Bergqvist , Anna Delin , Jonas Fransson

We develop a numerical model that reproduces the thermal equilibrium and the spin transfer mechanisms in magnetic nanomaterials. We analyze the coherent two-particle spin exchange interaction and the electron-electron collisions. Our study…

Mesoscale and Nanoscale Physics · Physics 2021-04-01 O. Morandi

We introduce a highly sensitive and relatively simple technique to observe magnetization motion in single Ni nanoparticles, based on charge sensing by electron tunneling at millikelvin temperature. Sequential electron tunneling via the…

Mesoscale and Nanoscale Physics · Physics 2018-01-17 W. C. Jiang , G. Nunn , P. Gartland , D. Davidović

Problems of strongly interacting electrons can be greatly simplified by reducing them to effective quantum spin models. The initial step is renormalization of the Hamiltonian into a lower energy subspace. The positive and negative U Hubbard…

Strongly Correlated Electrons · Physics 2007-05-23 A. Auerbach

We utilize simulations of spin-polarized electron scattering by a chain of localized quantum spins to show that energy and linear momentum conservation laws impose strong constraints on the properties of magnetic excitations induced by spin…

Mesoscale and Nanoscale Physics · Physics 2020-11-11 Alexander Mitrofanov , Sergei Urazhdin

The interplay between intrinsic and surface/interface-induced magnetic anisotropies strongly in- fluences magnetization processes in nanomagnetic systems. We develop a micromagnetic theory to describe the field-driven reorientation in…

Mesoscale and Nanoscale Physics · Physics 2016-07-12 A. A. Leonov , U. K. Roessler , A. N. Bogdanov

Magnetization of a spin1/2 set is determined by means of their individual wave function. The theoretical treatment based on the fundamental axioms of quantum mechanics and solving explicitly Schr\"odinger equation gives the evolution of…

Quantum Physics · Physics 2023-08-22 Tarek Khalil , Daniel Grucker