共查询到19条相似文献,搜索用时 515 毫秒
1.
计算分析了处于单模Fabry-Pérot腔内的无相互作用玻色-爱因斯坦凝聚体在引入自旋轨道耦合作用下的色散关系. F-P腔为冷原子系统提供了量子化的光晶格,利用紧束缚近似和平均场近似进行二次量子化,选取合适的腔参数得到单原子缀饰态能级的具体表达式.两束弱的Raman激光和外加磁场作用于玻色-爱因斯坦凝聚体,实现了有效的自旋轨道耦合,提供了一个人工规范势,使玻色-爱因斯坦凝聚体中产生了沿腔轴方向一维的高度可控的狄拉克点. 相似文献
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本系列文章一共4篇,在电磁学和电动力学框架内用尽量科普的方式分别介绍磁单极的若干奇特性质.本篇文章主要介绍狄拉克磁单极是如何展示矢量势的规范变换的.我们首先简要介绍规范变换与规范对称性及狄拉克磁单极与狄拉克弦,然后讨论狄拉克磁单极与规范变换的联系.我们显式演示狄拉克弦摆动产生的规范变换,弦摆动区域对场点所张的立体角正比于规范变换的变换函数.磁偶极子则可以由两个无穷靠近的正反狄拉克磁单极构成.相应两条狄拉克弦位置的变化都对应磁偶极子矢量势的规范变换,特别当两条弦重合时弦效应相互抵消,只剩下纯的磁偶极子.传统的由磁偶极子产生的矢量势的规范变换则可以图像化为组成磁偶极子的正反狄拉克磁单极的狄拉克弦的摆动.我们显式地计算了位于坐标原点弦为直线的狄拉克磁单极,并进一步构造了没有奇异的吴大峻-杨振宁磁单极. 相似文献
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《原子与分子物理学报》2021,(2)
计算分析了处于单模Fabry-Pérot腔内的无相互作用玻色-爱因斯坦凝聚体在引入自旋轨道耦合作用下的色散关系.F-P腔为冷原子系统提供了量子化的光晶格,利用紧束缚近似和平均场近似进行二次量子化,选取合适的腔参数得到单原子缀饰态能级的具体表达式.两束弱的Raman激光和外加磁场作用于玻色-爱因斯坦凝聚体,实现了有效的自旋轨道耦合,提供了一个人工规范势,使玻色-爱因斯坦凝聚体中产生了沿腔轴方向一维的高度可控的狄拉克点. 相似文献
4.
本文深入研究了孤子干涉过程中的相位演化特性及其背后的拓扑矢势.基于一维非线性薛定谔方程的双孤子解,发现波函数密度零点广泛存在于拓展的复平面内,并且每一个密度零点对应狄拉克磁单极的矢势场.矢势场是由周期排布的具有相反磁荷的狄拉克磁单极对组成.通过观察磁单极子的运动,可以方便地理解干涉过程中的相位演化特征.特别发现,一对正负磁单极对在实轴上的碰撞恰好对应波函数相位在节点处的π跃变.此外,还对比讨论了线性波包干涉动力学中的狄拉克磁单极.结果表明狄拉克磁单极势广泛存在于波场的干涉现象之中,并且磁单极在拓展的复平面内分布特征可用于区分线性干涉和非线性干涉过程背后的拓扑性质. 相似文献
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谢元栋 《原子与分子物理学报》2016,(4):717-724
研究了一维光格中旋量玻色—爱因斯坦凝聚体的自旋磁子和自旋波.求出了自旋磁子和自发磁化强度.用经典方法求得了均匀体系的自旋波和能级以及激光调制下的自旋波和能级.特别是在连续极限近似下,求得了马丢函数波及其能级. 相似文献
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谢元栋 《原子与分子物理学报》2016,33(2):717-724
研究了一维光格中旋量玻色—爱因斯坦凝聚体的自旋磁子和自旋波。求出了自旋磁子和自发磁化强度。用经典方法求得了均匀体系的自旋波和能级以及激光调制下的自旋波和能级。特别是在连续极限近似下,求得了马丢函数波及其能级。 相似文献
11.
M. Faber A.N. Ivanov A. Müller N.I. Trotskaya M. Zach 《The European Physical Journal C - Particles and Fields》1999,7(4):685-695
The magnetic monopole condensate is calculated in the dual Monopole Nambu–Jona–Lasinio model with dual Dirac strings suggested
in [1,2] as a functional of the dual Dirac string shape. The calculation is carried out in the tree approximation in the scalar
monopole–antimonopole collective excitation field. The integration over quantum fluctuations of the dual–vector monopole–antimonopole
collective excitation field around the Abrikosov flux line and string shape fluctuations are performed explicitly. We claim
that there are important contributions of quantum and string shape fluctuations to the magnetic monopole condensate.
Received: 3 June 1998 / Revised version: 1 September 1998 / Published online: 19 November 1998 相似文献
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M. Faber A. N. Ivanov N. I. Troitskaya 《Zeitschrift fur Physik C Particles and Fields》1997,74(4):721-726
We propose a model where a condensate of monopole-antimonopole pairs leads to confinement. Magnetic monopoles are considered as massless fermion fields interacting via local four-monopole interaction of the Nambu-Jona-Lasinio kind leading to monopole condensation. Condensation of magnetic monopole currents and any derivative of them are obtained. It is shown that the bosonized version of this Monopole Nambu-Jona- Lasinio (MNJL) model is reducing to London’s theory of dual superconductivity within Dirac’s extension of Maxwell’s Electrodynamics. The affinity of the MNJL-model with Compact Quantum Electrodynamics is discussed. 相似文献
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William J. Marciano 《International Journal of Theoretical Physics》1978,17(4):275-286
We review some properties of magnetic monopoles in non-Abelian gauge theories. Removal of Dirac string singularities and generalizations of the Wu-Yang solution that follow from this procedure are described. A discussion of the possible relevance of monopoles in strong interaction models and their role in quark confinement schemes is given. The magnetic monopole soliton discovered by 't Hooft and Polyakov, the first order formalism developed by Bogomolny, and extensions of these ideas are illustrated.Work supported in part by the U.S. Energy Research and Development Administration under Contract No. EY-76-C-02-2232B*000. 相似文献
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J. P. Hsu 《Foundations of Physics》1977,7(11-12):801-812
We study the magnetic monopoles in non-Abelian gauge theories. The exact static, spherically symmetric solutions of the magnetic monopoles in both Yang-Mills and unified gauge theories are obtained. The energyE of the static system is calculable and it is either zero or infinite. The existence of the magnetic monopole solution is a consequence of symmetry rather than dynamics. We propose a new definition of the electromagnetic field tensor, which relates the static solution of gauge fields and the magnetic monopole solution. Experimental implications are discussed. 相似文献
16.
In this paper, we examine the Dirac monopole in the framework of Off-Shell Electromagnetism, the five-dimensional U(1) gauge
theory associated with Stueckelberg–Schrodinger relativistic quantum theory. After reviewing the Dirac model in four dimensions,
we show that the structure of the five-dimensional theory prevents a natural generaliza tion of the Dirac monopole, since
the theory is not symmetric under duality transforma tions. It is shown that the duality symmetry can be restored by generalizing
the electromagnetic field strength to an element of a Clifford algebra. Nevertheless, the generalized framework does not permit
us to recover the phenomenological (or conventional) absence of magnetic monopoles. 相似文献
17.
It is shown that, unlike the case of (vacuum) solutions describing isolated bodies, conformal Killing fields are not excluded by the structure of vacuum gravitational magnetic monopoles at null infinity. The resulting dilation must be constant. This brings support to the viewpoint that such solutions might have a role to play in the understanding of gravitational entropy and time's arrow. If, in addition, a Maxwellian magnetic monopole (Dirac string singularity) is available, the ratio of the total magnetic charge (magnetic mass) over the total electric charge (mass) can be identified. This common feature between the gravitational and the electromagnetic interaction finds its origin in the space-time topology. 相似文献
18.
G. E. Volovik 《JETP Letters》1999,70(12):792-796
Two exotic objects are still not identified experimentally in chiral superfluids and superconductors. These are the half-quantum vortex, which plays the part of the Alice string in relativistic theories [A. S. Schwarz, Nucl. Phys. B 208, 141 (1982)], and the hedgehog in the Î field, which is the counterpart of the Dirac magnetic monopole. These two objects of different dimensionality are topologically connected. They form a combined object which is called a nexus [John M. Cornwall, hep-th/9911125; Phys. Rev. D 59, 125015 (1999); Phys. Rev. D 58, 105028 (1998)] or center monopole [N. N. Chernodub, M. I. Polikarpov, A. I. Veselov and M. A. Zubkov, Nucl. Phys. Proc. Suppl. 73, 575 (1999)] in relativistic theories. Such a combination will permit the observation of half-quantum vortices and monopoles in several realistic geometries. 相似文献
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We analyze the interplay of topological objects in four-dimensional QCD at finite temperature on the lattice. The distributions of color magnetic monopoles in the maximum abelian gauge are computed around instantons. Studies are performed in both pure and full QCD and in both the confinement and deconfinement phase. We find an enhanced probability for monopoles inside the core of an instanton on gauge field average. This is independent of the topological charge definition used. For specific gauge field configurations we visualize the situation graphically. Moreover the correlation of monopole loops and instantons with the chiral condensate is investigated. Strong evidence is found that clusters of the quark condensate and topological objects coexist locally on individual configurations. 相似文献