Related papers: S-mixing and quantum tunneling of the magnetizatio…
We review the present state of theory and experiments on the quantum tunneling of magnetization in mesoscopic spin systems. Most attention is paid to the relaxation of magnetization in the molecular complexes Mn12 and Fe8. The role of the…
The strong influence of nuclear spins on resonant quantum tunneling in the molecular cluster Fe_8 is demonstrated for the first time by comparing the relaxation rate of the standard Fe_8 sample with two isotopic modified samples: (i) 56_Fe…
We show that the dynamic magnetic susceptibility and the superparamagnetic blocking temperature of an Fe8 single molecule magnet oscillate as a function of the magnetic field Hx applied along its hard magnetic axis. These oscillations are…
The quantum tunneling effects between two metallic plates are studied using the time dependent density functional theory. Results show that the tunneling is mainly dependent on the separation and the initial local field of the interstice…
The quantum tunneling of the magnetization vector between excited levels are studied theoretically in single-domain ferromagnetic nanoparticles with biaxial crystal symmetry placed in an external magnetic field at an arbitarily directed…
The spin relaxation in the molecular magnet \Mn12 is investigated by a novel type of high-frequency magnetic spectroscopy. By reversing the external magnetic field the intensities of the $|\pm 10>\to |\pm 9>$ transitions within the ground…
A Mn30 molecular cluster is established to be the largest single-molecule magnet (SMM) discovered to date. Magnetization versus field measurements show coercive fields of about 0.5 T at low temperatures. Magnetization decay experiments…
A Mn4 single-molecule magnet (SMM) is used to show that quantum tunneling of magnetization (QTM) is not suppressed by moderate three dimensional exchange coupling between molecules. Instead, it leads to an exchange bias of the quantum…
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…
Magnetization measurements made in small fields as a function of temperature reveal an unusual equilibrium below 900 mK for the molecular nano-magnet Fe_8. Measurements of the relaxation of the magnetization demonstrate that the approach to…
We study macroscopic quantum tunneling of the magnetic moment in a single-domain particle placed above the surface of a superconductor. Such a setup allows one to manipulate the height of the energy barrier, preserving the degeneracy of the…
We show that the S/F/S Josephson $\varphi_0$-junction permits detection of macroscopic quantum tunneling and quantum oscillation of the magnetic moment by measuring the ac voltage across the junction. Exact expression for the tunnel…
Magnetic quantum tunneling in a single molecule magnet (SMM) has been studied in experiments that combine microwave spectroscopy with high sensitivity magnetic measurements. By monitoring spin-state populations in the presence of microwave…
We investigate the effect of dynamic nuclear spin fluctuation on quantum tunneling of the magnetization (QTM) in the molecular magnet Fe8 by increasing the nuclei temperature using radio frequency (RF) pulses before the hysteresis loop…
We argue that to explain recent resonant tunneling experiments on crystals of Mn$_{12}$ and Fe$_8$, particularly in the low-T limit, one must invoke dynamic nuclear spin and dipolar interactions. We show the low-$T$, short-time relaxation…
It is shown that a single molecular magnet placed in a rapidly oscillating magnetic field displays the phenomenon of quenching of tunneling processes. The results open a way to manipulate the quantum states of molecular magnets by means of…
We study macroscopic quantum coherence in antiferromagnetic molecular magnets in the presence of magnetic fields. Such fields generate artificial tunnel barriers with externally tunable strength. We give detailed semi-classical predictions…
Molecular nanomagnets, besides promising to open new frontiers in technology, have attracted huge interest in the scientific community because they can exhibit the phenomenon known as quantum tunnelling of the magnetization, i.e. coherent…
Recent progress in experiment on quantum tunnelling of the magnetic moment in mesoscopic systems will be reviewed. The emphasis will be made on measurements of individual nanoparticles. These nanomagnets allow one to test the border between…
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…