相关论文: Resonant Spin Tunneling in Randomly Oriented Nanos…
A Landau-Zener multi-crossing method has been used to investigate the tunnel splittings in high quality Mn$_{12}$-acetate single crystals in the pure quantum relaxation regime and for fields applied parallel to the magnetic easy axis. With…
The conductance profiles of magnetic transition metal atoms, such as Fe, Co and Mn, deposited on surfaces and probed by a scanning tunneling microscope (STM), provide detailed information on the magnetic excitations of such nano-magnets. In…
A distribution of internal transverse magnetic fields has been observed in single molecule magnet (SMM) Mn12-BrAc in the pure magnetic quantum tunneling (MQT) regime. Magnetic relaxation experiments at 0.4 K are used to produce a hole in…
Magnetization measurements of Mn12 molecular nanomagnets with spin ground states of S = 10 and S = 19/2 showresonance tunneling at avoided energy level crossings. The observed oscillations of the tunnel probability as a function of the…
In a recent paper, cond-mat/0404041, J. Vanacken et al. reported experimental studies of crystals of Mn12-ac molecular nanomagnets in pulsed magnetic fields with sweep rates up to 4000 T/s. Steps in the magnetization curve were observed.…
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…
A high resolution inelastic neutron scattering (INS) study of fully deuterated Mn$_{12}$-acetate provides the most accurate spin Hamiltonian parameters for this prototype single molecule magnet so far. The Mn$_{12}$-clusters deviate from…
A scanning tunneling microscope (STM) with a magnetic tip that has a sufficiently strong spin-polarization can be used to map the sample's spin structure down to the atomic scale but usually lacks the possibility to absolutely determine the…
Fully-relativistic first-principles calculations of the Fe(001) surface demonstrate that resonant surface (interface) states may produce sizeable tunneling anisotropic magnetoresistance in magnetic tunnel junctions with a single magnetic…
Interest in the magnetism of organic compounds is growing because of new organic magnets, spin-based electronics and the diverse properties of magnetic edge states in graphene nanoribbons. Electron spin resonance spectroscopy combined with…
We report point by point measurements below the blocking temperature of the magnetic relaxation of Mn$_{12}$-acetate as a function of magnetic field applied along the easy axis of magnetization. Unexpectedly complex structure is observed…
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…
The tunneling of a giant spin at excited levels is studied theoretically in mesoscopic magnets with a magnetic field at an arbitrary angle in the easy plane. Different structures of the tunneling barriers can be generated by the…
We present measurements of magnetic tunnel junctions made using a self-assembled-monolayer molecular barrier. Ni/octanethiol/Ni samples were fabricated in a nanopore geometry. The devices exhibit significant changes in resistance as the…
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…
In the last years there has been a great interest in magnetic systems formed by a cluster of transition metal ions covalently bonded via superexchange bridges, embedded in a large organic molecule. Following the synthesis and the structural…
Precise magnetic hysteresis measurements of small single crystals of Mn$_{12}$ acetate of spin 10 have been conducted down to 0.4 K using a high sensitivity Hall magnetometer. At higher temperature (>1.6K) step-like changes in magnetization…
We present a method for precisely measuring the tunnel splitting in single-molecule magnets using electron-spin resonance, and use these measurements to precisely and independently determine the underlying transverse anisotropy parameter,…
In the last years there has been a great interest in magnetic systems formed by a cluster of transition metal ions covalently bonded via superexchange bridges, embedded in a large organic molecule. Following the synthesis and the structural…
We report Hall sensor measurements of the magnetic relaxation of Mn$_{12}$ acetate as a function of magnetic field applied along the easy axis of magnetization. Data taken at a series of closely-spaced temperatures between 0.24 K and 1.4 K…