Balance equation approach to the hot-electron transport in electric and magnetic fields is reformulated. The balance equations are re-derived from the Boltzmann equation. A new expression for the distribution function...Balance equation approach to the hot-electron transport in electric and magnetic fields is reformulated. The balance equations are re-derived from the Boltzmann equation. A new expression for the distribution function is reported in the present paper. It is homogeneous steady solution of the Boltzmann equation in constant relaxation time approximation. It holds when or . As an example, the mobility of 2D electron gas in the GaAs-AlGaAs heterojunction is computed as a function of electric field and magnetic field.展开更多
We study the effect of potential and thermal gradient induced non-equilibrium magnetization in quasi1-d itinerant magnets.A semi-phenomenological theory is employed in conjunction with the drift-diffusion model forthi...We study the effect of potential and thermal gradient induced non-equilibrium magnetization in quasi1-d itinerant magnets.A semi-phenomenological theory is employed in conjunction with the drift-diffusion model forthis study.Using the methods of non-equilibrium thermodynamics,we derive the transport currents correspondingto charge,heat,and magnetization flows in the presence of non-equilibrium magnetization textures.It is shown howtime-dependent magnetic textures give rise to charge and thermal currents even in the absence of external potential andthermal gradients through spin pumping.The presence of dynamical textures also affect the thermodynamic parametersof the system.As an application,we consider the case of a helimagnet.展开更多
Finite Element Method is used in this article to analyze the stress of CR superferric magnet.Magnetic force and the stress caused by this force are calculated.The thermal stress and strain of the coil caused by coolin...Finite Element Method is used in this article to analyze the stress of CR superferric magnet.Magnetic force and the stress caused by this force are calculated.The thermal stress and strain of the coil caused by cooling down is also analyzed.The result will be taken as a check for the design of the coil and coilcase,and also as a reference for the optimization of further design and quench protection.展开更多
Using the Kane-Mele Hamiltonian, Dirac theory and self-consistent Born approximation, we investigate the effect of dilute charged impurity on the electronic heat capacity and magnetic susceptibility of two-dimensional...Using the Kane-Mele Hamiltonian, Dirac theory and self-consistent Born approximation, we investigate the effect of dilute charged impurity on the electronic heat capacity and magnetic susceptibility of two-dimensional ferromagnetic honeycomb structure of group-Ⅳ elements including silicene, germanene and stanene within the Green's function approach. We also find these quantities in the presence of applied external electric field. Our results show that the silicene(stanene) has the maximum(minimum) heat capacity and magnetic susceptibility at uniform electric fields. From the behavior of theses quantities, the band gap has been changed with impurity concentration, impurity scattering strength and electric field. The analysis on the impurity-dependent magnetic susceptibility curves shows a phase transition from ferromagnetic to paramagnetic and antiferromagnetic phases. Interestingly, electronic heat capacity increases(decreases) with impurity concentration in silicene(germanene and stanene) structure.展开更多
文摘Balance equation approach to the hot-electron transport in electric and magnetic fields is reformulated. The balance equations are re-derived from the Boltzmann equation. A new expression for the distribution function is reported in the present paper. It is homogeneous steady solution of the Boltzmann equation in constant relaxation time approximation. It holds when or . As an example, the mobility of 2D electron gas in the GaAs-AlGaAs heterojunction is computed as a function of electric field and magnetic field.
文摘We study the effect of potential and thermal gradient induced non-equilibrium magnetization in quasi1-d itinerant magnets.A semi-phenomenological theory is employed in conjunction with the drift-diffusion model forthis study.Using the methods of non-equilibrium thermodynamics,we derive the transport currents correspondingto charge,heat,and magnetization flows in the presence of non-equilibrium magnetization textures.It is shown howtime-dependent magnetic textures give rise to charge and thermal currents even in the absence of external potential andthermal gradients through spin pumping.The presence of dynamical textures also affect the thermodynamic parametersof the system.As an application,we consider the case of a helimagnet.
文摘Finite Element Method is used in this article to analyze the stress of CR superferric magnet.Magnetic force and the stress caused by this force are calculated.The thermal stress and strain of the coil caused by cooling down is also analyzed.The result will be taken as a check for the design of the coil and coilcase,and also as a reference for the optimization of further design and quench protection.
文摘Using the Kane-Mele Hamiltonian, Dirac theory and self-consistent Born approximation, we investigate the effect of dilute charged impurity on the electronic heat capacity and magnetic susceptibility of two-dimensional ferromagnetic honeycomb structure of group-Ⅳ elements including silicene, germanene and stanene within the Green's function approach. We also find these quantities in the presence of applied external electric field. Our results show that the silicene(stanene) has the maximum(minimum) heat capacity and magnetic susceptibility at uniform electric fields. From the behavior of theses quantities, the band gap has been changed with impurity concentration, impurity scattering strength and electric field. The analysis on the impurity-dependent magnetic susceptibility curves shows a phase transition from ferromagnetic to paramagnetic and antiferromagnetic phases. Interestingly, electronic heat capacity increases(decreases) with impurity concentration in silicene(germanene and stanene) structure.
