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Related papers: Phonoemissive Spin Tunneling in Molecular Nanomagn…

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The correlation between the magnetic moment in ferromagnetic alloys and the tunneling spin polarization in ferromagnet-insulator-superconductor tunneling experiments has been a mystery. The measured spin polarization for Fe, Co, Ni, and…

Materials Science · Physics 2009-10-31 Tat-Sang Choy , Jian Chen , Selman Hershfield

The magnetization of the prototypical molecular magnet Mn12-acetate exhibits a series of sharp steps at low temperatures due to quantum tunneling at specific resonant values of magnetic field applied along the easy c-axis. An abrupt…

Mesoscale and Nanoscale Physics · Physics 2010-01-21 M. P. Sarachik , S. McHugh

A quantum theory of magnetization dynamics of a nanomagnet as a sequence of scatterings of each electron spin with the macrospin state of the magnetization results in each encounter a probability distribution of the magnetization recoil…

Mesoscale and Nanoscale Physics · Physics 2012-03-30 Yong Wang , L. J. Sham

We theoretically study the transport properties of a supramolecular spin valve, consisting of a carbon nanotube with two attached magnetic molecules, weakly coupled to metallic contacts. The emphasis is put on analyzing the change of the…

Mesoscale and Nanoscale Physics · Physics 2019-03-19 A. Plominska , I. Weymann

Capacitance of a nanoscale system is usually thought of having two contributions, a classical electrostatic contribution and a quantum contribution dependent on the density of states and/or molecular orbitals close to the Fermi energy. In…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 Yu-Ning Wu , Xiao-Guang Zhang , Hai-Ping Cheng

Magnetic switching of a single-molecule magnet (SMM) due to spin-polarized current is investigated theoretically. The charge transfer between the electrodes takes place via the lowest unoccupied molecular orbital (LUMO) of the SMM.…

Mesoscale and Nanoscale Physics · Physics 2007-08-29 Maciej Misiorny , Józef Barnas

We demonstrate a technique that enables ferromagnetic resonance (FMR) measurements of the normal modes for magnetic excitations in individual nanoscale ferromagnets, smaller in volume by a factor of 1000 than can be probed by other methods.…

Materials Science · Physics 2009-11-11 J. C. Sankey , P. M. Braganca , A. G. F. Garcia , I. N. Krivorotov , R. A. Buhrman , D. C. Ralph

We present a microscopic theory for magnetization relaxation in metallic ferromagnets of nanoscopic dimensions that is based on the dynamic spin response matrix in the presence of spin-orbit coupling. Our approach allows the calculation of…

Mesoscale and Nanoscale Physics · Physics 2015-02-10 A. T. Costa , R. B. Muniz

We investigate the inelastic spin-flip rate for electrons in a quantum dot due to their contact hyperfine interaction with lattice nuclei. In contrast to other works, we obtain a spin-phonon coupling term from this interaction by taking…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Veniamin A. Abalmassov , Florian Marquardt

Quantum effects fundamentally engender exotic physical phenomena in macroscopic systems, which advance next-generation technological applications. Rotational tunneling that represents the quantum phenomenon of the librational motion of…

We probe the spin dynamics in a thin magnetic film at ferromagnetic resonance by nuclear resonant scattering of synchrotron radiation at the 14.4 keV resonance of $^{57}$Fe. The precession of the magnetization leads to an apparent reduction…

Atoms confined in a magnetic trap can escape by making spin-flip Majorana transitions due to a breakdown of the adiabatic approximation. Several papers have studied this process for atoms with spin $F = 1/2$ or $F= 1$. The present paper…

Quantum Physics · Physics 2009-11-13 D. M. Brink , C. V. Sukumar

Spin tunneling in molecular magnets controlled by dipole-dipole interactions (DDI) in the disordered state has been considered numerically on the basis of the microscopic model using the quantum mean-field approximation. In the actual case…

Statistical Mechanics · Physics 2014-01-07 D. A. Garanin

Below 360 mK, Fe8 magnetic molecular clusters are in the pure quantum relaxation regime. We showed recently that the predicted ``square-root time'' relaxation is obeyed, allowing us to develop a new method for watching the evolution of the…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 W. Wernsdorfer , T. Ohm , C. Sangregorio , R. Sessoli , D. Gatteschi , C. Paulsen

The mechanism of magnetization reversal in single-domain ferromagnetic particles is of interest in many applications, in most of which losses must be minimized. In cancer therapy by hyperthermia the opposite requirement prevails: the…

Other Condensed Matter · Physics 2009-11-13 P. F. de Chatel , I. Nandori , J. Hakl , S. Meszaros , K. Vad

We report on resonant tunneling magnetoresistance via localized states through a ZnSe semiconducting barrier which can reverse the sign of the effective spin polarization of tunneling electrons. Experiments performed on Fe/ZnSe/Fe planar…

Materials Science · Physics 2009-11-11 J. Varalda , A. J. A. de Oliveira , D. H. Mosca , J. -M. George , M. Eddrief , M. Marangolo , V. H. Etgens

Starting from a phenomenological Hamiltonian originally written in terms of angular momentum operators we derive a new quantum angle-based Hamiltonian that allows for a discussion on the quantum spin tunneling. The study of the…

Quantum Physics · Physics 2007-05-23 D. Galetti

Current theories still fail to give a satisfactory explanation of the observed quantum phenomena in the relaxation of the magnetisation of the molecular cluster Mn12 acetate. In the very low temperature regime, Prokof'ev and Stamp recently…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 W. Wernsdorfer , R. Sessoli , D. Gatteschi

Nambu-Goldstone theorem provides gapless modes to both relativistic and nonrelativistic systems. The Nambu-Goldstone bosons in insulating magnets are called magnons or spin-waves and play a key role in magnetization transport. We review…

Mesoscale and Nanoscale Physics · Physics 2017-02-24 Kouki Nakata , Pascal Simon , Daniel Loss

A model describing spin-polarized current via discrete energy levels of a metallic nanoparticle, which has strongly asymmetric tunnel contacts to two ferromagnetic leads, is presented. In absence of spin-relaxation, the model leads to a…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Y. G. Wei , C. E. Malec , D. Davidović
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