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Related papers: Mesoscopic Spin Tunneling in Molecular Crystals

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The two-dimensional (2D) semiconductor molybdenum disulfide (MoS2) has attracted widespread attention for its extraordinary electrical, optical, spin and valley related properties. Here, we report on spin polarized tunneling through…

We consider the role of quantum effects in the transfer of hyrogen-like species in enzyme-catalysed reactions. This study is stimulated by claims that the observed magnitude and temperature dependence of kinetic isotope effects imply that…

Quantum Physics · Physics 2010-05-25 Jacques P. Bothma , Joel Gilmore , Ross H. McKenzie

We use a quantum Monte Carlo method to investigate various classes of 2D spin models with long-range interactions at low temperatures. In particular, we study a dipolar XXZ model with U(1) symmetry that appears as a hard-core boson limit of…

Quantum Gases · Physics 2016-11-11 Michal Maik , Philipp Hauke , Omjyoti Dutta , Jakub Zakrzewski , Maciej Lewenstein

The quantum tunneling of the magnetization vector are studied theoretically in single-domain ferromagnetic nanoparticles placed in an external magnetic field at an arbitrarily directed angle in the $ZX$ plane. We consider the…

Statistical Mechanics · Physics 2009-10-31 Rong Lu , Jia-Lin Zhu , Zhi-Rong Liu , Lee Chang , Bing-Lin Gu

Spin relaxation due to atom-atom collisions is measured for magnetically trapped erbium and thulium atoms at a temperature near 500 mK. The rate constants for Er-Er and Tm-Tm collisions are 3.0 times 10^-10 cm^3 s^-1 and 1.1 times 10^-10…

Atomic Physics · Physics 2015-05-14 Colin B. Connolly , Yat Shan Au , S. Charles Doret , Wolfgang Ketterle , John M. Doyle

The first measurements of magnetization hysteresis loops on diluted single crystal of [(Pc)2Ho]-TBA+ (Pc: phthalocyaninato, TBA: tetrabutylammonium) in the subkelvin temperature range are reported. Characteristic staircase-like structure…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 N. Ishikawa , M. Sugita , W. Wernsdorfer

The X-ray absorption near-edge structure (XANES) of Mn in a spin-crossover compound, [Mn$^{\textrm{III}}$(taa)], was studied in pulsed high magnetic fields up to 37T. By applying magnetic fields to the low-temperature low-spin (LS) state,…

Strongly Correlated Electrons · Physics 2015-03-14 Jim Long Her , Yasuhiro H. Matsuda , Motohiro Nakano , Yasuhiro Niwa , Yasuhiro Inada

Mesoscopic conductors are electronic systems of sizes in between nano- and micrometers, and often of reduced dimensionality. In the phase-coherent regime at low temperatures, the conductance of these devices is governed by quantum…

Mesoscale and Nanoscale Physics · Physics 2008-03-27 Michael Wimmer , Matthias Scheid , Klaus Richter

A scanning tunneling microscope (STM) can probe the inelastic spin excitations of single magnetic atoms in a surface via spin-flip assisted tunneling. A particular and intriguing case is the Mn dimer case. We show here that the existing…

Mesoscale and Nanoscale Physics · Physics 2022-08-31 F. Delgado , J. Fernández-Rossier

The variation with microwave frequency and temperature of previously reported anomalous peaks in the EPR spectra of Mn12-acetate, under large transverse fields, reveals that the molecular easy magnetization axes are tilted with respect to…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 S. Hill , S. Takahashi , R. S. Edwards , J. M. North , N. S. Dalal

The nonlinear dynamical response of Mn$_{12}$ single-molecule magnets is experimentally found to be very large, quite insensitive to the spin-lattice coupling constant, and displaying peaks reversed with respect to classical…

Mesoscale and Nanoscale Physics · Physics 2016-08-31 F. Luis , V. Gonzalez , A. Millan , J. L. Garcia-Palacios

Spin currents may be generated by applying bias voltages V to the nanostructures even in the absence of spin-active ferromagnetic interfaces. Most theoretical proposals concentrate on a concrete spin-orbit interaction and on the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Yuli V. Nazarov

We demonstrate an electrically controlled high-spin (S=5/2) to low-spin (S=1/2) transition in a three-terminal device incorporating a single Mn2+ ion coordinated by two terpyridine ligands. By adjusting the gate-voltage we reduce the…

Tunneling of the spins in the Fe$_8$ molecular magnet from a metastable ground state to an excited state is accompanied by a decay of these spins to the global ground state, and an increase of the crystal temperature. We measured this…

Mesoscale and Nanoscale Physics · Physics 2019-10-29 Maayan Yaari , Amit Keren

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

A mesoscopic spin valve is used to determine the effective spin polarization of electrons tunneling from and into ferromagnetic transition metals at finite voltages. The tunneling spin polarization from the ferromagnet (FM) slowly decreases…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 S. O. Valenzuela , D. J. Monsma , C. M. Marcus , V. Narayanamurti , M. Tinkham

Any evolving system can change of state via thermal mechanisms (hopping a barrier) or via quantum tunneling. Most of the time, efficient classical mechanisms dominate at high temperatures. This is why an increase of the temperature can…

Materials Science · Physics 2014-02-14 M. Minissale , E. Congiu , S. Baouche , H. Chaabouni , A. Moudens , F. Dulieu , M. Accolla , S. Cazaux , G. Manico , V. Pirronello

We investigate macroscopic quantum tunneling of a Bose condensate and how it is affected by the interatomic interaction. We study the dynamics of a condensate falling under gravity and scattering on a Gaussian potential barrier that models…

Statistical Mechanics · Physics 2009-11-07 L. Salasnich , A. Parola , L. Reatto

We investigate the spin tunnelling of spin-1 Bose-Einstein condensates in a linearly sweeping magnetic field with a mean-field treatment. We focus on the two typical alkali Bose atoms $^{87}Rb$ and $^{23}Na$ condensates and study their…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Guan-Fang Wang , Li-Bin Fu , Jie Liu

Recent radio frequency scanning tunneling spectroscopy (rf-STS) experiments have demonstrated nuclear and electron spin excitations up to $\pm12\hbar$ in a single molecular spin quantum dot (qudot). Despite the profound experimental…