We have theoretically studied the nucleation of superconductivity in doubly connected superconductors in the form of long superconducting cylinders. The giant vortex states are investigated with the nonlinear Ginzburg...We have theoretically studied the nucleation of superconductivity in doubly connected superconductors in the form of long superconducting cylinders. The giant vortex states are investigated with the nonlinear Ginzburg-Landau theory. The solutions of Ginzburg-Landau equations are solved numerically with relaxation method. The quantum size effect is clearly shown through the calculation of free energy.展开更多
The smoothness of the solutions to the full Landau equation for Fermi-Dirac particles is investigated.It is shown that the classical solutions near equilibrium to the Landau-Fermi-Dirac equation have a regularizing ef...The smoothness of the solutions to the full Landau equation for Fermi-Dirac particles is investigated.It is shown that the classical solutions near equilibrium to the Landau-Fermi-Dirac equation have a regularizing effects in all variables (time,space and velocity),that is,they become immediately smooth with respect to all variables.展开更多
Magnetization orientation of a nanoscale ferromagnet can be manipulated by an electric current via spin-transfer torque(STT) effect,which holds great promise in the applications of non-volatile magnetic random access ...Magnetization orientation of a nanoscale ferromagnet can be manipulated by an electric current via spin-transfer torque(STT) effect,which holds great promise in the applications of non-volatile magnetic random access memory(MRAM) and spintorque oscillators.We review the fundamental mechanism and experimental progress of the STT effect.Then,different formula of STT torque has been classified,which can be added to the conventional Landau-Lifshitz-Gilbert equation.After that,we show some simulation results that mainly concern the STT-driven vortex dynamics,magnetization oscillations excited by a perpendicular polarizer,and the detail dynamics by in-plane and out-of-plane dual spin polarizers.展开更多
基金The project supported by Natural Science Foundation from Beijing Normal University.Acknowledgments H. Zhao wishes to thank Profs. Fang-Lin Peng, Jue- Lian Shen, and Jia-Cai Nie for helpful discussions
文摘We have theoretically studied the nucleation of superconductivity in doubly connected superconductors in the form of long superconducting cylinders. The giant vortex states are investigated with the nonlinear Ginzburg-Landau theory. The solutions of Ginzburg-Landau equations are solved numerically with relaxation method. The quantum size effect is clearly shown through the calculation of free energy.
基金Project supported by the National Natural Science Foundation of China(No.11101188)
文摘The smoothness of the solutions to the full Landau equation for Fermi-Dirac particles is investigated.It is shown that the classical solutions near equilibrium to the Landau-Fermi-Dirac equation have a regularizing effects in all variables (time,space and velocity),that is,they become immediately smooth with respect to all variables.
基金support by the National Natural Science Foundation of China(Grant Nos.11074046,11274241,51171047 and 51222103)the Shuguang Program of Shanghai Education Commission(Grant No.09SG22)the New Century Educational Talents Plan of Chinese Education Ministry(Grant No.NCET-10-0603)
文摘Magnetization orientation of a nanoscale ferromagnet can be manipulated by an electric current via spin-transfer torque(STT) effect,which holds great promise in the applications of non-volatile magnetic random access memory(MRAM) and spintorque oscillators.We review the fundamental mechanism and experimental progress of the STT effect.Then,different formula of STT torque has been classified,which can be added to the conventional Landau-Lifshitz-Gilbert equation.After that,we show some simulation results that mainly concern the STT-driven vortex dynamics,magnetization oscillations excited by a perpendicular polarizer,and the detail dynamics by in-plane and out-of-plane dual spin polarizers.
