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Related papers: Quantum nucleation in a single-chain magnet

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In this paper, we investigate the thermal quantum correlations in a semiconductor double quantum dot system. The device comprises a single electron in a double quantum dot subjected to a longitudinal magnetic field and a transverse magnetic…

Quantum Physics · Physics 2024-12-30 Vinicius Leitão , Onofre Rojas , Moises Rojas

We calculate the magnetic-field and temperature dependence of all quantum corrections to the ensemble-averaged conductance of a network of quantum dots. We consider the limit that the dimensionless conductance of the network is large, so…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Joern N. Kupferschmidt , Piet W. Brouwer

In type II hard superconductors the irreversible magnetization shows an impressive variety of different magnetic field dependencies. In this paper we will try to describe the M(H) relation at fixed temperature To by a numerical model in…

Superconductivity · Physics 2007-05-23 J. Vanacken , L. Trappeniers , K. Rosseel , W. Boon

We calculate the magnetisation relaxation in the short-time regime for an ensemble of nanomagnets in the presence of a low-frequency external AC biasing field, at temperatures lower than the magnetic anisotropy energy of the individual…

Condensed Matter · Physics 2007-05-23 G. Rose , P. C. E. Stamp

Features of thermally-activated magnetization switching have been studied in a FeCoB nanomagnet using the N\'eel model. A method of a high-precision measurement of the coercive field, retention time, {\Delta} and the size of the switching…

Mesoscale and Nanoscale Physics · Physics 2020-02-05 Vadym Zayets

The entanglement in a general mixed spin chain with arbitrary spin $S$ and 1/2 is investigated in the thermodynamical limit. The entanglement is witnessed by the magnetic susceptibility which decides a characteristic temperature for an…

Quantum Physics · Physics 2009-11-13 Xiang Hao , Shiqun Zhu

We investigate the quantum evolution of spin states of a single molecular magnet in a local electric field. The decoherence of a $\texttt{\{}\emph{Cu}_3\texttt{\}}$ single molecular magnet weakly coupled to a thermal bosonic environment can…

Quantum Physics · Physics 2015-06-18 Xiang Hao , Xiaoqun Wang , Chen Liu , Shiqun Zhu

In this paper, we combine thermal effects with Landau-Zener (LZ) quantum tunneling effects in a dynamical Monte Carlo (DMC) framework to produce satisfactory magnetization curves of single-molecule magnet (SMM) systems. We use the giant…

Mesoscale and Nanoscale Physics · Physics 2010-10-14 Gui-Bin Liu , Bang-Gui Liu

We report measurements on magnetization reversal in the Fe$_8$ molecular magnet using fast pulsed magnetic fields of 1.5 kT/s and in the temperature range of 0.6-4.1 K. We observe and analyze the temperature dependence of the reversal…

Mesoscale and Nanoscale Physics · Physics 2014-09-11 S. N. Jammalamadaka , J. Vanacken , V. V. Moshchalkov , Saül Vélez , J. Tejada , Ferran Macià

The coercive field of permanent magnets decays with temperature. At non-zero temperature the system can overcome a finite energy barrier through thermal fluctuations. Using finite element micromagnetic simulations, we quantify this effect,…

Materials Science · Physics 2016-03-29 Simon Bance , Johann Fischbacher , Alexander Kovacs , Harald Oezelt , Franz Reichel , Thomas Schrefl

The integral relaxation time describing the thermoactivated escape of a uniaxial quantum spin system interacting with a boson bath is calculated analytically in the whole temperature range. For temperatures T much less than the barrier…

Statistical Mechanics · Physics 2009-10-31 D. A. Garanin

The relaxation rate and temperature-dependent switching field curve of a spherical magnetic nanocluster are calculated by taking into account the effect of surface anisotropy via an effective anisotropy model. In particular, it is shown…

Materials Science · Physics 2009-11-13 P. -M. Dejardin , H. Kachkachi , Yu. P. Kalmykov

Recent experiments have reported on controlled nucleation of individual skyrmions in chiral magnets. Here we show that in magnetic ultra-thin films with interfacial Dzyaloshinskii-Moriya interaction, single skyrmions of different radii can…

Strongly Correlated Electrons · Physics 2021-09-14 Sebastian A. Diaz , Daniel P. Arovas

We investigate the thermal activated magnetisation reversal in a single ferromagnetic nanoparticle with uniaxial anisotropy using Monte Carlo simulations. The aim of this work is to reproduce the reversal magnetisation by uniform rotation…

Materials Science · Physics 2009-11-10 Denis Ledue , Pierre-Emmanuel Berche , Renaud Patte

We measure the temperature, magnetic-field, and current dependence for the switching of nanomagnets by a spin-polarized current. Depending on current bias, switching can occur between either two static magnetic states or a static state and…

The quantum nanomagnets show interesting site-dependent magnetic properties as a function of the temperature and the external magnetic field. In the paper we present the results of calculations for a finite quantum spin ladder with two…

Mesoscale and Nanoscale Physics · Physics 2018-09-11 K. Szałowski , P. Kowalewska

The role of spin polarized reservoirs in quantum tunneling of magnetization and relaxation processes in a single molecular magnet (SMM) is investigated theoretically. The SMM is exchange-coupled to the reservoirs and also subjected to a…

Mesoscale and Nanoscale Physics · Physics 2016-08-16 Maciej Misiorny , Józef Barnas

The thermal remagnetization (TR), i.e. the reentrance of magnetization upon heating in a steady-field demagnetized sample, is a common feature to the four types of polycrystalline permanent magnets, mainly utilized for practical purposes,…

Materials Science · Physics 2007-05-23 R. Schumann , L. Jahn

The magnetic properties of Cu97Co3 and Cu90Co10 granular alloys were measured over a wide temperature range (2 to 300K). The measurements show an unusual temperature dependence of the coercive field. A generalized model is proposed and…

Materials Science · Physics 2009-11-10 W. C. Nunes , W. S. D. Folly , J. P. Sinnecker , M. A. Novak

Magnetization reversal in a ferromagnetic nanowire which is much narrower than the exchange length is believed to be accomplished through the thermally activated growth of a spatially localized nucleus, which initially occupies a small…

Statistical Mechanics · Physics 2007-05-23 Robert S. Maier