Pauli Equation for Non-Abelian Dyons in Moduli Space

Undertaking the study of behaviour of an extended dyon moving in the generalized electromagnetic field of another non-Abelian dyon in moduli space, Dirac's equation has been solved for energy eigenvalues and it has been shown that spin momentum of an interacting non-Abelian dyon behaves as extra energy source. Introducing suitable spinors, the Pauli equation for a spin-1/2 non-Abelian dyon moving in the field of another non-Abelian dyon has been solved in moduli space and it has been shown that ad hoc introduction of spin in the system of two non-Abelian dyons perceptibly modifies the energy eigenvalues and eigenfunctions of bound states of the system.     

Magnetic symmetry and dyons

A self-consistent theory of dyons in Abelian and non-Abelian limits has been formulated in terms of an extra magnetic symmetry and topological magnetic charge. It has been shown that the restricted gauge potential describes the fields of dyons in terms of two regular (time-like) potentials only when recourse is made to the duality of topological (magnetic) and isocolour (electric) charges. Choosing a suitable Lagrangian density for the system of dyons in non-Abelian gauge theory, the field equations, energy-momentum tensor, Hamiltonian and momentum densities have also been derived and the conservation of the four-linear momentum and the total angular momentum has been demonstrated.     

BPS Monopoles in Moduli Space under SU(2) Gauge Potential

Solving Dirac equation for a BPS monopole moving in the field of another BPS monopole in moduli space, it has been shown that spin momentum of the interacting monopole behaves as an extra energy source. The possibilities of splitting of the energy levels of the system have been explored.     

含外规范场和动力学费米子自能的狄拉克算符及费米子凝聚

将非阿贝尔规范理论中狄拉克算符行列式的计算从传统的只能含有硬费米子质量项的情况推广到可以含有动量相关的费米子自能的情况，并且行列式与费米子凝聚的计算都被推广到使之能够含有任意的外规范场. 关键词： 费米子自能 外规范场 狄拉克算符的行列式 费米子凝聚     

Equations of motion for a classical color particle in external non-Abelian fermionic and bosonic fields

On the basis of principles of gauge and reparametrization invariance of a real-valued Lagrangian, construction of the action describing the dynamics of a classical color-charged particle interacting with background non-Abelian gauge and fermion fields is considered. The cases of the linear and quadratic dependence of a Lagrangian on the background fermion field are discussed. It is shown that, in both cases, there exist an infinite number of interaction terms. From an iteration scheme, examples of construction of the first few currents and sources induced by a moving particle with non-Abelian charge are given. It is shown that these quantities by a suitable choice of parameters exactly reproduce additional currents and sources obtained previously in [1] on the basis of heuristic considerations.     

Berry联络与吴－杨单极势

通过研究一半整数自旋值的中性粒子在球对称磁场中的Ｂｏｒｎ－Ｏｐｐｅｎｈｅｉｍｅｒ方程，发现在自旋空间Ｂｅｒｒｙ联络呈非阿贝尔形式．在绝热近似下，Ｂｅｒｒｙ联络相当于阿贝尔形式的吴－杨单极场．由于拓扑的非平庸性，利用纤维丛中截面的概念研究了位形空间的动力学，发现中心势场中粒子的角动量和能量均取量子化值，但数值发生移动，这是纯几何起源的现象．     

Berry's Connection and Wu-Yang's Monopole Potential

By studying the Born-Oppenheimer equation for a neutral spin-1／2 particle moving in a spherically symmetrical magnetic field,the non-Abelian Berry's connection in the internal space is found.In the adiabatic approximation,it displays the role of Wu-Yang's monopole.The dynamics for the configurational space is studied by using the concept of section in fibre bundle.Though the angular momentum and energy are quantized,their values are moved.The origination of this phenomenon is geometrical.     

Probing anisotropic superfluidity in atomic Fermi gases with Rashba spin-orbit coupling

Motivated by the prospect of realizing a Fermi gas with a synthetic non-Abelian gauge field, we investigate theoretically a strongly interacting Fermi gas in the presence of a Rashba spin-orbit coupling. As the twofold spin degeneracy is lifted by spin-orbit interaction, bound pairs with mixed singlet and triplet components emerge, leading to an anisotropic superfluid. We calculate the relevant physical quantities, such as the momentum distribution, the single-particle spectral function, and the spin structure factor, that characterize the system.     

Angular Momentum Operator and Fermion-Pair Creation for Non-Abelian Fields

We study the extended structure of non-Abelian dyons, the generalized electromagnetic field and the resulting residual angular momentum in the interior as well as exterior regions of the dyon, and it has been demonstrated that at the dyonic centre there exists no well-defined U(1) charge symmetry and the density of residual angular momentum becomes infinity. The mechanism of creation of a fermionic pair at the dyonic core involving the extremely high density of residual angular momentum has been developed, which leads to baryon-number nonconservation in the presence of non-Abelian dyons. The fermion-number–breaking amplitudes in the presence of a non-Abelian dyon have been analyzed and are not suppressed by exp(– const/e ²). Further, the relevant properties of left-handed fermions in a non-Abelian field has been summarized and the zeroth-order approximation is described. Within this approximation the density of the fermion-number–breaking condensate is found to be O(1), i.e. to be independent of the coupling constant and of the vacuum expectation value of the Higgs field.     

Dynamical stabilization of runaway potentials at finite density

We study four-dimensional non-Abelian gauge theories with classical moduli. Introducing a chemical potential for a flavor charge causes moduli to become unstable and start condensing. We show that the moduli condensation in the presence of a chemical potential generates non-Abelian field strength condensates. These condensates are homogeneous but non-isotropic. The end point of the condensation process is a stable homogeneous, but non-isotropic, vacuum in which both gauge and flavor symmetries and the rotational invariance are spontaneously broken. Possible applications of this phenomenon for the gauge theory/string theory correspondence and in cosmology are briefly discussed.     

Finite-mode regularization of the fermion functional integral

We present a regularization of the fermion functional integral in the presence of a gauge field, obtained by projecting the fermion fields on a finite subspace of the fermion wave functions. We find the basis that ensures manifest gauge covariance. We are able, in this way, to develop a non-perturbative method of calculation and test it by calculating the triangle anomalies in different models. All the calculations are carried out on a finite-size momentum space lattice. Finally we briefly discuss the zero-mode problem.     

Quantal Conserved Charges in Gauge Theory

Starting from the configuration-space generating functional for gauge theory obtained by using the Faddeev-Popov method,the conservation laws at the quantum level for the gauge-invariant system are derived.Appling to non-Abel Chern-Simons(CS)theory,the quantum BRS conserved charge and quantuml conserved angular momentum for the non-Abelian CS fields coupled to Fermion field are deduced.The property of fractional spin in CS theory is discussed.     

Non-Abelian gauge potentials for ultracold atoms with degenerate dark states

We show that the adiabatic motion of ultracold, multilevel atoms in spatially varying laser fields can give rise to effective non-Abelian gauge fields if degenerate adiabatic eigenstates of the atom-laser interaction exist. A pair of such degenerate dark states emerges, e.g., if laser fields couple three internal states of an atom to a fourth common one under pairwise two-photon-resonance conditions. For this so-called tripod scheme we derive general conditions for truly non-Abelian gauge potentials and discuss special examples. In particular we show that using orthogonal laser beams with orbital angular momentum an effective magnetic field can be generated that has a monopole component.     

Chern–Simons particles with nonstandard gravitational interaction

The model of nonrelativistic particles coupled to nonstandard (2+1)-gravity is extended to include Abelian or non-Abelian charges coupled to Chern–Simons gauge fields. Equivalently, the model may be viewed as describing the (Abelian or non-Abelian) anyonic dynamics of Chern–Simons particles coupled, in a reparameterization invariant way, to a translational Chern–Simons action. The quantum 2-body problem is described by a nonstandard Schr?dinger equation with a noninteger angular momentum depending on energy as well as particle charges. Some numerical results describing the modification of the energy levels by these charges in the confined regime are presented. The modification involves a shift as well as splitting of the levels. Received: 16 March 2001 / Published online: 13 June 2001     

电子在均匀磁场中的状态--对自旋的讨论之二

求得了在均匀磁场中的电子沿着磁场方向的动量、角动量分量和能量的共同本征态。计算了电子产生的磁矩,由此继续论证所谓的总磁矩和总角动量其实质是相对论性的轨道磁矩和轨道角动量的看法。     

Quantization of non-abelian gauge theory. I. Gauge invariant Hamiltonian formulation

An essentially gauge invariant canonical Hamiltonian formulation is given for a non-Abelian Yang-Mills system coupled to a fermion field. The Hamiltonian contains only unconstrained dynamical variables, which in the quantum version satisfy canonical equal time commutation relations.     

Ground state energy of two dimensional electrons in strong magnetic fields: Small clusters in fractional occupations

We diagonalize numerically the Hamiltonian for a two-dimensional system of up to seven interacting via Coulomb force electrons in a strong magnetic field using the symmetric gauge. The effect of positive charge background is taken into account. We find significant downward cusps for certain values of the total angular momentum corresponding to fractional occupation of the lowest Landau level in agreement with results obtained by using Landau gauge. This commensurate energy for fractional occupation is interpreted in terms of the “closest configuration” in the space of single particle angular momentum.     

Gauge fields, geometric phases, and quantum adiabatic pumps

Quantum adiabatic pumping of charge and spin between two reservoirs (leads) has recently been demonstrated in nanoscale electronic devices. Pumping occurs when system parameters are varied in a cyclic manner and sufficiently slowly that the quantum system always remains in its ground state. We show that quantum pumping has a natural geometric representation in terms of gauge fields (both Abelian and non-Abelian) defined on the space of system parameters. Tunneling from a scanning tunneling microscope tip through a magnetic atom could be used to demonstrate the non-Abelian character of the gauge field.