共查询到20条相似文献,搜索用时 0 毫秒
1.
We consider a particle moving on a cone and bound to its tip by 1/r or harmonic oscillator potentials. When the deficit angle of the cone divided by 2π is a rational number, all bound classical orbits are closed. Correspondingly, the quantum system has accidental degeneracies in the discrete energy spectrum. An accidental SU(2) symmetry is generated by the rotations around the tip of the cone as well as by a Runge-Lenz vector. Remarkably, some of the corresponding multiplets have fractional “spin” and unusual degeneracies. 相似文献
2.
3.
Bohlin transformation for a circular singular oscillator in a constant magnetic field is considered. It is shown that this transformation leads to a two-dimensional Kepler problem with an additional centrifugal potential from the constant magnetic field whose strength decreases inversely proportional to the distance from the center of attraction of the system. The energy spectrum of the considered system is obtained. 相似文献
4.
The moving neutral system of two Coulomb charges on a plane subject to a constant magnetic field B perpendicular to the plane is considered. It is shown that the composite system of finite total mass is bound for any center-of-mass momentum P and magnetic field strength; the energy of the ground state is calculated accurately using a variational approach. Its accuracy is cross-checked in a Lagrange-mesh method for B=1 a.u. and in a perturbation theory at small B and P. The constructed trial function has the property of being a uniform approximation of the exact eigenfunction. For a Hydrogen atom and a Positronium a double perturbation theory in B and P is developed and the first corrections are found algebraically. A phenomenon of a sharp change of energy behavior for a certain center-of-mass momentum and a fixed magnetic field is indicated. 相似文献
5.
S. Djurović Z. Mijatović M. Pavlov R. Kobilarov B. T. Vujičić 《Journal of Applied Spectroscopy》1997,64(5):578-586
Measurements of the additional shift of the Hβ spectral line emitted by a plasma in a magnetic field are performed. The magnitudes
of the shift are distinguished by good reproducibility. The magnetic field strength was 0.5 and 2.1 T. Comparison is made
of the Hβ line profiles recorded in the presence of the magnetic field and without it, all other things being equal. Consideration
is given to a number of possible causes of the additional shift (they include the dependence of the shift on the density of
electrons, their temperature, and on the velocity of the plasma flux). The additional shift of the Hβ line in the presence
of the magnetic field is qualitatively substantiated.
Presented at the 1th Belorussian-Yugoslavian Symposium on the Physics and Diagnostics of Laboratory and Astrophysical Plasmas,
1–3 July, 1996, Misnk.
Institute of Physics, 4, Obradović St., Novi Sad, 21000, Yugoslavia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol.
64, No. 5, pp. 566–574, September–October, 1997. 相似文献
6.
We study the coherent state excitation of spins in square nanodots induced by a magnetic microwave field. We present a new mechanism of spin reversal in nanodots. That is, the microwave field directly induces the reversal of the coherent‐state spins instead of indirectly through the magnetic vortex. We obtain the space distribution of coherent‐state spins in terms of a quantum theory, and calculate the time of spin reversal. This spin‐reversal process may be used to serve as a storage mechanism of binary information. 相似文献
7.
We investigate the ratio of spin precession frequency to orbital frequency for a spinning charged particle confined to circular
orbit in the equatorial plane of a compact object, with a uniform magnetic field, as described by the Wald and the Ernst potentials.
In order to see the difference in behaviours for particles with differentg values we consider the cases of electron and proton separately. 相似文献
8.
9.
The explicit form of operators of kinetic momenta and spin projection for a neutral particle with an anomalous magnetic moment in constant homogeneous electromagnetic field is found. The possible applications of the obtained results in neutrino physics are considered. 相似文献
10.
11.
12.
在有效质量近似理论下,采用有效垒高方法,研究了在沿超晶格生长方向加一有限磁场时磁耦合效应对半无限半导体超晶格中表面电子态的影响.当考虑超晶格中阱层和垒层之间电子有效质量的差别时,沿超晶格生长方向的磁场将导致磁耦合效应的出现.研究结果表明,磁耦合效应不仅引起表面电子能级的量子化,而且表面电子能级的大小及其在表面附近的局域程度也依赖于磁场的大小和朗道指数.此外,研究表明布洛赫波数的虚部可以作为一个衡量表面电子态局域程度的物理量.
关键词:
超晶格中的电子态
表面态
磁场 相似文献
13.
C.L. Yang R.R. Du L.N. Pfeiffer K.W. West 《Physica E: Low-dimensional Systems and Nanostructures》2006,34(1-2):232
In an ultra-clean two-dimensional electron system (2DES), we have observed the magnetoplasmon resonance (MPR) through its microwave-photoconductivity, concurrently with the microwave-induced resistance oscillations (MIRO) and zero-resistance states (ZRS). It is found that the MIRO/ZRS is strongly suppressed by a moderate magnetic field () parallel to the 2DES, while the MPR is robust against a parallel magnetic field. These findings have not been addressed by current models proposed to explain the MIRO/ZRS. 相似文献
14.
The torque exerted by a magnetic field on a sphere with permanent electric dipole moment moving steadily in a dielectric fluid is calculated to lowest order in the dipole moment. Hence the force exerted on a steadily rotating sphere with electric dipole moment is found by Onsager symmetry. The modification from the vacuum values of torque and force depends only on the slip parameter and the static dielectric constant of the fluid. It is suggested that for a macroscopic ferro electric sphere the calculated effects could be measured experimentally without great difficulty. 相似文献
15.
We have calculated the effect of a magnetic field on the evolution of angular momentum eigenfunctions of a charged particle. An additional harmonic potential is supplemented to trap the wave packet. We find the probability density of the wave function is oscillating in the radial direction with a time period determined by the strength of the effective harmonic potential. When the magnetic field is along the z direction, if the initial wave function is an eigenfunction of ${\hat{L}}_{z}$, the probability density of the particle remains axis-symmetric. While for the case of an eigenfunction of ${\hat{L}}_{x}$, it is anisotropic in the x−y plane and rotates with a time period inverse proportional to the strength of the external magnetic field. We also extend the results in a phenomenological way to the case with an external magnetic field that varies harmonically in time. 相似文献
16.
K. Kamishima T. TokueD. Miyata Y. SatoF. Kadonome T. NodaK. Kakizaki N. HiratsukaY. Imanaka T. Takamasu 《Journal of magnetism and magnetic materials》2012,324(6):1106-1111
We have prepared pyrolytic carbon samples from triethylamine on diamond powder in applied magnetic field of 6 T and investigated their magnetic properties. A ferromagnetic sample was obtained from the pyrolysis products even at room temperature, with spontaneous magnetization of 6.4 A m2/kg at 300 K, which is twice as large as that of the sample prepared without diamond powder. Therefore, the diamond powder seems to promote the formation of a three-dimensional ferromagnetic structure in pyrolytic carbon. 相似文献
17.
本文讨论了带电粒子在正交的电场和磁场中于不同条件下的旋轮线轨迹,并讨论了这些不同形状的旋轮线是怎样由圆轮的纯滚动形成的,使带电粒子的运动过程更加直观,并且运用物理方法导出了旋轮线曲率半径的普遍公式. 相似文献
18.
Acceleration of a test particle in the gravitational field of central mass with a large number of magnetic monopoles 下载免费PDF全文
In a Kerr-Newman-Kasuya field we have obtained expressions of the acceleration effect and also studied the special case (v^i=0). We find that in this field, the acceleration of a falling particle has both radial and transverse components. The acceleration effects of electric charge q and magnetic charge φ are also discussed, separately. 相似文献
19.
We derive various sum rules for the time-displaced structure function of a classical one-component plasma subjected to an external uniform magnetic field. When the plasma has some translational invariance (i.e., homogeneous or translation-invariant along the field), we find that there are long-wavelength oscillations with well-defined frequencies. The results are obtained from linear response and macroscopic electrodynamics, as well as from the microscopic equations of motion (BBGKY hierarchy). In the presence of the magnetic field, the time-displaced structure function has a polynomial decay at large distances, even in the homogeneous case. When the plasma has no translational invariance, examples show a more complicated temporal behaviour in the long-length-scale limit, involving a superposition of oscillations over a continuous range of frequencies. 相似文献
20.
基于一维弹塑性磁流体力学程序(SSS-MHD),研究了反场构型(FRC)等离子体靶在磁驱动固体套筒压缩过程中强磁场对α粒子能量约束效应,分析了α粒子的非局域和局域自加热对FRC等离子靶压缩峰值温度的影响,以及α粒子能量在整个压缩过程中端部损失效应。等离子体部分采用多温单流体的模型,能量的计算中引入了DT离子、电子及α粒子多成分温度的能量方程,同时考虑了等离子体压缩过程热平衡下的核反应和非局域自加热问题。研究结果表明,磁化靶聚变等离子体在压缩过程中具有较好的稳定性,能够保持刚性转子的靶结构,压缩过程形成的强磁场能够将α粒子的能量约束在O点附近的区域,有利于等离子体靶的点火及燃烧;α粒子对等离子体的自加热效应主要集中在等离子体电流中心区,而非等离子体中心轴处;α粒子对DT等离子体局域和非局域自加热过程存在差异,局域自加热过程的功率大于非局域自加热过程的功率,FRC等离子靶压缩峰值状态温度相差0.5倍。在反场构型的刮离层区,α粒子的能量端部损失在FRC等离子体靶的压缩和膨胀过程中逐渐增大。 相似文献