Related papers: Self-organized patterns of macroscopic quantum tun…
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…
Renormalized tunnel splitting with a finite distribution in the biaxial spin model for molecular magnets is obtained by taking into account the dipolar interaction of enviromental spins. Oscillation of the resonant tunnel splitting with a…
We study the macroscopic quantum tunneling of magnetization of the F=1 spinor condensate interacting through dipole-dipole interaction with an external magnetic field applied along the longitudinal or transverse direction. We show that the…
We study the magnetic relaxation of a system of localized spins interacting through weak dipole interactions, at a temperature large with respect to the ordering temperature but low with respect to the crystal field level splitting. The…
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…
Combination of the thermal effet in magnetic deflagration with resonance spin tunneling controlled by the dipole-dipole interaction in molecular magnets leads to the increase of the deflagration speed in the dipolar window near tunneling…
We report measurements and theoretical analysis of resonant spin tunneling in randomly oriented nanospheres of a molecular magnet. Amorphous nanospheres of Mn$_{12}$ acetate have been fabricated and characterized by chemical, infrared, TEM,…
Dissipative spin-tunneling transitions at biased resonances in molecular magnets such as Mn-12 Ac are controlled by the dipolar field that can bring the system on and off resonance. It is shown that this leads to spin relaxation in form of…
Motivated by the idea of using simple macroscopic examples to illustrate the physics of complex systems, we modify a historic experimental setup in which interacting floating magnets spontaneously self-assemble into ordered clusters. By…
Below 360 mK, Fe magnetic molecular clusters are in the pure quantum relaxation regime and we show that the predicted square-root time relaxation is obeyed, allowing us to develop a new method for watching the evolution of the distribution…
We study the formation and dynamics of dipolar rings composed by microscopic ferromagnetic ellipsoids, which self-assemble in water by switching the direction of the applied field. We show how to manipulate these fragile structures and…
The dynamic interplay of transport, electrostatic, and magnetic effects in the resonant tunneling through ferromagnetic quantum wells is theoretically investigated. It is shown that the carrier-mediated magnetic order in the ferromagnetic…
The spin-reversal in dilute Li$_2$(Li$_{1-x}$Fe$_{x}$)N with $x < 1$ % is dominated by resonant quantum tunneling of spatially well-separated states. We report on the effect of finite couplings between those states that give rise to…
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 examine the quantum tunneling of magnetization in molecular spin in weak interaction with a bath subject to Redfield master equation. By designing a microscopic model for a multilevel spin system using only a generic Hamiltonian and…
Decoherence processes in crystals of molecular magnets are prototypical for interacting electronic spin systems. We analyze the Landau-Zener dynamics of the archetypical TbPc$_2$ complex diluted in a diamagnetic monocrystal. The dependence…
Using a microscopic theory based on the density matrix formalism we investigate quantum revivals and collapses of the charge polarization and charge current dynamics in mesoscopic rings driven by short asymmetric electromagnetic pulses. The…
We study the dynamical magnetization process in the ordered ground-state phase of the transverse Ising model under sweeps of magnetic field with constant velocities. In the case of very slow sweeps and for small systems studied previously…
The reversal of the magnetization of crystals of molecular magnets that have a large spin and high anisotropy barrier generally proceeds below the blocking temperature by quantum tunneling. This is manifested as a series of controlled steps…
The ground state of colloidal magnetic particles in a modulated channel are investigated as function of the tilt angle of an applied magnetic field. The particles are confined by a parabolic potential in the transversal direction while in…