共查询到20条相似文献,搜索用时 109 毫秒
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用Bessel函数积分对圆环电流磁矢势及均匀带电圆环电势作进一步的计算分析,引申出磁感应强度及电场强度新的级数表达式,分析讨论了所得结果. 相似文献
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分析两种均匀磁介质分界面上有长载流导线的场和电流分布,指出磁感应强度B=B(r)φ径向对称分布是由径向对称分布的总电流j=j(r)ez(包括传导电流和磁化电流)所激发,探讨了传导电流的分布与磁感应强度B、磁场强度H和磁化电流的分布的关系。 相似文献
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圆形线电流的磁感应强度 总被引:43,自引:11,他引:32
用磁标势法计算了圆形线电流的磁感应强度。利用这个结果证明了圆形线电流平面中心的磁感应强度有极小值,给出了圆环回路的自感系数的计算公式。 相似文献
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利用微元法和对应性推证了均匀带电直线与均匀带电圆弧产生的电场等效; 利用微元法和对称性推
导了均匀带电圆弧在圆心的场强公式; 利用结论巧妙解答有关线性带电体的场强计算问题 相似文献
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Boyong Jia Zhongyuan Yu Yumin Liu Zhihui Chen Wenjie Yao Wei Zhao Han Ye Hao Feng 《Physica E: Low-dimensional Systems and Nanostructures》2009,42(1):82-85
The electronic structures of GaAs/Al0.35Ga0.65As concentric double rings are calculated based on the effective mass envelope function theory, with and without the applied electric and magnetic field along the growth direction. The Hamiltonian matrix elements are determined through the Fourier transform method. As the heterostructure evolves from a single ring to the concentric double rings, our simulation is performed on the bound state energies of the electron and the hole. The results show that the energy levels undulate with the evolution of the ring. The applied magnetic field increases the ground state energies both of the electron and of the hole, as well as the transition energy between the first conduction subband and valence subband. However, the electric field decreases the electronic energies linearly. 相似文献
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J. Planelles J.I. Climente F. Rajadell 《Physica E: Low-dimensional Systems and Nanostructures》2006,33(2):370-375
The electronic states of semiconductor quantum rings (QRs) under tilted magnetic fields are studied in the framework of the effective mass and envelope function approximations. For an axial field, the orbital Zeeman contribution prevails leading to the well-known Aharanov–Bohm spectrum, but it slowly decreases as the magnetic field direction declines. For an in-plane field, only the diamagnetic shift survives and it leads to the formation of double quantum well solutions, this result being relevant for experimental techniques which use in-plane magnetic fields to determine the spin of QR ground states. We also investigate the magnetic response of partially overlapped QRs, which are characteristic of high-density samples of self-assembled rings, and find that the spectrum is quite sensitive to ring coupling. 相似文献
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介观金属双环系统中的持续电流和量子能谱 总被引:7,自引:1,他引:7
崔元顺 《原子与分子物理学报》2006,23(3):527-531
基于电荷的不连续性,对处于外磁场中的介观双环系统进行量子化.假设系统在电荷表象中具有变换的对称性,通过求解电流和Hamilton算符的本征值方程,给出介观金属环互感系统中的量子电流和能谱关系;分析和研究了介观金属环中量子电流和能谱的性质.结果表明,持续电流和量子能谱不仅与外磁场、介观双环参数有关,而且还明显地依赖于电荷的量子化性质. 相似文献
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首先叙述了由单个轴向磁化环所产生的磁场,并就两个永磁环所产生的纵向磁场进行了分析.对于两个沿同一方向磁化的永磁体环,沿磁环中心线将会产生一个强度较为均匀的轴向磁场.如果两者的磁化方向相反,则在两磁铁间的区域将产生一个纵向的梯度磁场,其磁场强度介于-B0到+B0之间.设计制造了一个高梯度的轴向磁场,其磁场梯度为47.2Tm,测量结果与计算结果非常一致.文中还讨论了产生变梯度磁场的方法.由于永磁环所产生的磁场和螺线管的磁场较为相似,磁铁外部空间将有较大的漏场,最后还讨论了屏蔽漏场的问题. 相似文献
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We investigate theoretically the magnetoexciton states in semiconductor concentric quantum double rings using the multi-band effective mass theory. We find that a perpendicular magnetic field can lead to oscillations in the exciton energy which appear as kinks in the magneto-photoluminescence (PL) spectra as the magnetic field increases. The spatial distribution of the exciton over the rings depends sensitively on the thicknesses of the inner and outer rings. The tunneling coupling between the inner and outer rings and the heavy-hole and light-hole mixing results in different anticrossing behaviors. Exciton can be converted into a spatially separated type-II exciton by tuning the thickness, the inner and/or outer ring radius and the magnetic field. We show that this type I–type II transition is reflected in the oscillator strength of the PL spectrum which will be the experimental signature that will provide us with information about the spatial distribution of the exciton. 相似文献
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Aiming at the interaction and coalescence of bubbles in gas–liquid two-phase flow, a multi-field coupling model was established to simulate deformation and dynamics of multi-bubble in gas–liquid two-phase flow by coupling magnetic field, phase field, continuity equation, and momentum equation. Using the phase field method to capture the interface of two phases, the geometric deformation and dynamics of a pair of coaxial vertical rising bubbles under the applied uniform magnetic field in the vertical direction were investigated. The correctness of results is verified by mass conservation method and the comparison of the existing results. The results show that the applied uniform magnetic field can effectively shorten the distance between the leading bubble and the trailing bubble, the time of bubbles coalescence, and increase the velocity of bubbles coalescence. Within a certain range, as the intensity of the applied uniform magnetic field increases, the velocity of bubbles coalescence is proportional to the intensity of the magnetic field, and the time of bubbles coalescence is inversely proportional to the intensity of the magnetic field. 相似文献
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Ying-hua Ji Hai-mei Luo Jie Liu Hua-Ming Wan 《Physica E: Low-dimensional Systems and Nanostructures》2005,25(4):668-674
We propose a quantum Hamiltonian and obtain the relationship between external magnetic field and currents of three mesoscopic coupling rings. The impact of coupling on quantum current magnification in the system is studied. It is found that the quantum current magnification effect strongly depend on both the external magnetic flux and the coupling factors. As a result, by taking use of coupling rings, we can design some circuits to transfer and communicate signals. 相似文献
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The energies of the electron and hole weak-coupling polarons are determined in quantum rings of finite width in a uniform magnetic field. It is shown that polaron corrections exhibit oscillatory behavior as a function of a magnetic field. The effect of polaron corrections on the absorption and emission spectra of light by excitons in a quantum ring is considered. 相似文献
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This work presents a theoretical study of the energy spectrum of GaAs/AlGaAs concentric double quantum rings, under an applied magnetic field directed perpendicular to the ring plane. The Schrödinger equation for this system is solved in a realistic model consisting of rings with finite barrier potentials. Numerical results show that increasing the magnetic field intensity leads to oscillations in the ground state energy which, in contrast to the usual Aharonov-Bohm oscillations, do not have a well defined period, due to the coupling between inner and outer ring states. However, when one considers an elliptical geometry for the rings, the energy spectra of the inner and outer ring states are decoupled and the periodicity of the oscillations is recovered. 相似文献