Study Of Magnetic Dynamic Properties For Quantum Dots

The magnetic properties of single quantum dots and quasi two-dimensional quantum dot arrays have been studied by using standard Monte Carlo simulation method. Also, microcosmic magnetization behavior has been investigated by studying macroscopical magnetic parameters of single quantum dots and quantum dot arrays. Form the point Of view of numerical simulation we have explained the magnetic properties of the magnetic quantum dots which have been obtained in laboratory. The following items are the primary work of the thesis.1st. We have given a systematic discussion on the progress of nanometer science and technology, quantum effects of nano-material and the applications of quantum dots. Also, the basic theories of magnetism and material are introduced. The principle of Monte Carlo simulation method, a numerical calculation method used in the thesis, is present.2nd. We constructed single quantum dots (sphericity, single cubic structure), which contain different number of lattice. Magnetization dynamic properties of the single quantum dots have been studied by using Monte Carlo simulation method. The results indicate that the radium of quantum dot (R) and dipole interaction (D) have an important influence upon the magnetic properties of single quantum dots.3rd. We constructed a kind of quasi two-dimensional 4×4 quantum dot arrays. Systematically, the influence of dipole interaction (D) and exchange interaction (J) upon the magnetic properties of the quantum dot arrays have been investigated. The study indicates that exchange interaction (J) and temperature (T)have an important influence upon the magnetic properties of the quantum dot arrays. The simulated results are consistent with the experimental data.4th. Hexagonal lattice of quantum dot arrays and Hexagonal lattice of magnetic clusters have been structured in this segment. Magnetic dynamic properties of the two models have been studied, respectively. Compared with the experimental results, under given parameters, the simulated results of hysteresis loops for the quantum dot arrays are more consistent with the experimental results at room temperature.