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Related papers: Quantum phase interference and spin parity in Mn12…

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The independent control of two magnetic electrodes and spin-coherent transport in magnetic tunnel junctions are strictly required for tunneling magnetoresistance, while junctions with only one ferromagnetic electrode exhibit tunneling…

We use neutron diffraction to probe the magnetization components of a crystal of Mn12 single-molecule magnets. Each of these molecules behaves, at low temperatures, as a nanomagnet with spin S = 10 and strong anisotropy along the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 F. Luis , J. Campo , J. Gomez , G. J. McIntyre , J. Luzon , D. Ruiz-Molina

Spin polarized transport through a quantum dot coupled to ferromagnetic electrodes with noncollinear magnetizations is discussed in terms of nonequilibrium Green functions formalism in the finite-U slave boson mean field approximation. The…

Mesoscale and Nanoscale Physics · Physics 2021-12-10 D. Krychowski , S. Lipiński

We present low temperature magnetometry measurements on a new Mn3 single-molecule magnet (SMM) in which the quantum tunneling of magnetization (QTM) displays clear evidence for quantum mechanical selection rules. A QTM resonance appearing…

Mesoscale and Nanoscale Physics · Physics 2009-06-04 J. J. Henderson , C. Koo , P. L. Feng , E. del Barco , S. Hill , I. S. Tupitsyn , P. C. E. Stamp , D. N. Hendrickson

The ground state tunnel splitting for the biaxial spin model in the magnetic field, H = -D S_{x}^2 + E S_{z}^2 - g \mu_B S_z H_z, has been investigated using an instanton approach. We find a new type of spin instanton and a new quantum…

Soft Condensed Matter · Physics 2009-10-31 E. M. Chudnovsky , X. Martinez-Hidalgo

Single molecule magnets straddle the classical and quantum mechanical worlds, displaying many fascinating phenomena. They may have important technological applications in information storage and quantum computation. We review the physical…

Mesoscale and Nanoscale Physics · Physics 2010-08-06 Jonathan R. Friedman , Myriam P. Sarachik

The electronic structure and spin-dependent tunneling in epitaxial Fe/MgO/Fe(001) tunnel junctions are studied using first-principles calculations. For small MgO barrier thickness the minority-spin resonant bands at the two interfaces make…

Materials Science · Physics 2007-08-16 K. D. Belashchenko , J. Velev , E. Y. Tsymbal

Nanoscale magnetic tunnel junction plays a pivotal role in magnetoresistive random access memories. Successful implementation depends on a simultaneous achievement of low switching current for the magnetization switching by spin-transfer…

Applied Physics · Physics 2018-05-09 K. Watanabe , B. Jinnai , S. Fukami , H. Sato , H. Ohno

Starting from the canonical ensemble over the space of pure quantum states, we obtain an integral representation for the partition function. This is used to calculate the magnetisation of a system of N spin-1/2 particles. The results…

Quantum Physics · Physics 2013-09-13 Dorje C. Brody , Lane P. Hughston , Matthew F. Parry

The tunneling effect of a periodic potential with an asymmetric twin barrier per period is calculated using the instanton method. The model is derived from the Hamiltonian of a small ferromagnetic particle in an external magnetic field…

High Energy Physics - Theory · Physics 2014-11-18 J. -Q. Liang , H. J. W. Mueller-Kirsten , Jian-Ge Zhou , F. Zimmerschied , F. -C. Pu

We study the magnetic relaxation rate Gamma of the single-molecule magnet Mn_{12}-tBuAc as a function of magnetic field component H_T transverse to the molecule's easy axis. When the spin is near a magnetic quantum tunneling resonance, we…

Mesoscale and Nanoscale Physics · Physics 2013-02-21 S. T. Adams , E. H. da Silva Neto , S. Datta , J. F. Ware , C. Lampropoulos , G. Christou , Y. Myaesoedov , E. Zeldov , Jonathan R. Friedman

We report the existence of a sizeable quantum tunnelling splitting between the two lowest electronic spin levels of mononuclear Ni complexes. The level anti-crossing, or magnetic clock transition, associated with this gap has been directly…

The tunnel magnetoresistance (TMR) of F/O/F magnetic junctions, (F's are ferromagnetic layers and O is an oxide spacer) in the presence of magnetic impurities within the barrier, is investigated. We assume that magnetic couplings exist both…

Materials Science · Physics 2009-10-31 A. Vedyayev , D. Bagrets , A. Bagrets , B. Dieny

The conductance and tunnel magneto-resistance (TMR) of the double barrier magnetic tunnel junction with spin-valve sandwich (F/P/F) inserted between two insulating barrier, are theoretically investigated. It is shown, that resonant…

Condensed Matter · Physics 2009-11-10 N. Ryzhanova , G. Reiss , F. Kanjouri , A. Vedyayev

This thesis contains a thorough investigation of the quantum spin dynamics in Mn12-ac and Mn6 Single-molecule magnets. In particular, we have investigated the interplay between quantum tunneling of magnetization and nuclear spin dynamics in…

Mesoscale and Nanoscale Physics · Physics 2009-09-29 Andrea Morello

Controlling electronic transport through a single-molecule junction is crucial for molecular electronics or spintronics. In magnetic molecular devices, the spin degree-of-freedom can be used to this end since the magnetic properties of the…

By means of sequential and cotunneling spectroscopy, we study the tunnel couplings between metallic leads and individual levels in a carbon nanotube quantum dot. The levels are ordered in shells consisting of two doublets with strong- and…

Strongly Correlated Electrons · Physics 2012-05-02 K. Grove-Rasmussen , S. Grap , J. Paaske , K. Flensberg , S. Andergassen , V. Meden , H. I. Jørgensen , K. Muraki , T. Fujisawa

We reveal that the interplay between Rashba spin-orbit coupling and proximity-induced magnetization in a two-dimensional electron gas leads to peculiar transport properties and large anisotropy of magnetoresistance. While the related…

Mesoscale and Nanoscale Physics · Physics 2020-08-26 Chenghao Shen , Timothy Leeney , Alex Matos-Abiague , Benedikt Scharf , Jong E. Han , Igor Zutic

Quantum particles can penetrate potential barriers by tunneling (1). If that barrier is rotating, the tunneling process is modified (2,3). This is typical for electrons in atoms, molecules or solids exposed to strong circularly polarized…

The tunnel magnetoresistance (TMR) in the magnetic tunnel junction (MTJ) with embedded nanoparticles (NPs) was calculated in range of the quantum-ballistic model. The simulation was performed for electron tunneling through the insulating…

Mesoscale and Nanoscale Physics · Physics 2016-03-25 Arthur Useinov , Lin-Xiu Ye , Niazbeck Useinov , Te-Ho Wu , Chih-Huang Lai