Density Matrix Equation for a Bathed Small System and its Application to Molecular Magnets

Abstract

The technique of density matrix equation (DME) for a small system interacting with a bath is explained in detail. Special attention is given to the nonsecular DME that is needed in the vicinity of overdamped tunnelling resonances in molecular magnets (MM). The relaxation terms of the DME for MM are represented in the universal form that does not employ any unknown spin-lattice coupling constants and absorbs the information about the spin Hamiltonian in the exact basis states and transition frequencies. This makes adding new types of anisotropy easy and error-free. The Mathematica code is available from the author.

47 one-column PRE-style pages, 7 figures

References in corpus (9)

• Effects of D-strain, g-strain, and dipolar interactions on EPR linewidths of the molecular magnets Fe8 and Mn12
• Crossover between Thermally Assisted and Pure Quantum Tunneling in Molecular Magnet Mn12-Acetate
• Universal mechanism of spin relaxation in solids
• Symmetry of Magnetic Quantum Tunneling in Single Molecule Magnet Mn12-acetate
• Universal Decoherence in Solids
• Radiation- and Phonon-Bottleneck-Induced Tunneling in the Fe8 Single-Molecule Magnet
• Two-phonon spin-lattice relaxation of rigid atomic clusters
• Extended Debye Model for Molecular Magnets
• Energy Level Lifetimes in the Single-Molecule Magnet Fe_8 : Experiments and Simulations

Cited by in corpus (5)

• Multiple relaxation times in single-molecule magnets
• Intermolecular mechanism for multiple maxima in molecular dynamic susceptibility
• Geometric-phase interference in a Mn_{12} single-molecule magnet with four-fold rotational symmetry
• Are superparamagnetic spins classical?
• Nonlinear ac stationary response and dynamic magnetic hysteresis of quantum uniaxial superparamagnets