An introduction to topology in electrodynamics and the geometric phase con- cept is given. The form-invariance of the field-coupled Dirac equation is demon- strated, and it is shown, starting from the free Dirac equation, that demand of local phase invariance of the wave function dictates the presence of an elec- tromagnetic field. Afterwards the Dirac phase factor, Φ( C ), for a fixed-time loop is defined and discussed. It appears from The Principle of Local Phase Invariance that only the transverse part of the vector potential contributes to Φ( C ). The conditions ∇ × A T = 0 and ∇ · A T = 0 [A T being the transverse vector potential] in a certain finite spatial domain Ω do not imply that A T = 0 necessarily in Ω, as a certain integration involving A T over the domain outside Ω shows. The vector potential of a magnetic string with curvature and torsion is derived, and from this potential the result for a rectilinear magnetic string is obtained, In turn the Aharonov-Bohm effect is derived for a magnetic flux tube. Starting from the evolution operator in quantum physics an adiabatic theorem is established, and Berry's adiabatic geometric phase is introduced and discussed. An extended discussion shows that a geometric phase, called the Aharonov-Anandan phase, not restricted by the adiabatic principle can be introduced.
An introduction to topology in electrodynamics and the geometric phase con- cept is given. The form-invariance of the field-coupled Dirac equation is demon- strated, and it is shown, starting from the free Dirac equation, that demand of local phase invariance of the wave function dictates the presence of an elec- tromagnetic field. Afterwards the Dirac phase factor, Φ( C ), for a fixed-time loop is defined and discussed. It appears from The Principle of Local Phase Invariance that only the transverse part of the vector potential contributes to Φ( C ). The conditions ∇ × A T = 0 and ∇ · A T = 0 [A T being the transverse vector potential] in a certain finite spatial domain Ω do not imply that A T = 0 necessarily in Ω, as a certain integration involving A T over the domain outside Ω shows. The vector potential of a magnetic string with curvature and torsion is derived, and from this potential the result for a rectilinear magnetic string is obtained, In turn the Aharonov-Bohm effect is derived for a magnetic flux tube. Starting from the evolution operator in quantum physics an adiabatic theorem is established, and Berry's adiabatic geometric phase is introduced and discussed. An extended discussion shows that a geometric phase, called the Aharonov-Anandan phase, not restricted by the adiabatic principle can be introduced.
In this work, we make a review of the literature that the so-called Berry’s geometric phase. A recent issue, which has been employed in various areas of physics. For this, we use, in a number of references, in which many were critical to the theoretical foundation of this work. At first, we focus on the study of the time evolution of quantum systems governed by Hamiltonians operators whose time dependence is manifested by a set of parameters called classical fields. The adiabatic approximation, is justified mathematically when demonstrated the adiabatic theorem. Under these conditions, we obtain geometric phases - Berry’s phase - associated with these systems in different representations, each displaying its particularity. Finally, as a particular case of geometric phase, we studi from the viewpoint of duality transformations of Maxwell’s equations, the dual Aharonov-Bohm effect, extracting the geometric Berry’s phase associated with the dynamics of the magnetic monopole in the presence of the electric vector potential
The Berry phase [3] is traditionally understood as a geometric phase acquired during cyclic adiabatic evolution, often interpreted as the flux of an effective “magnetic field” through a solid angle in parameter space. In this thesis, we investigate situations in which a geometric phase arises even when no spatial solid angle is enclosed, revealing the limitations of the standard purely spatial interpretation. We first review the Berry phase for a spin-½ particle in a slowly varying magnetic field and analyze scenarios in which the system’s eigenstate is changed during the adiabatic evolution. We show that the resulting phase can be understood through a spacetime formulation analogous to the electrodynamic Aharonov–Bohm effect [1], where both “analogous magnetic” and “analogous electric” fields contribute through a spacetime surface integral. This framework clarifies how nonzero geometric phases can occur even when the projected spatial solid angle vanishes. We then extend this perspective to the Jahn–Teller 𝐸 ⊗ 𝑒 system. While a closed loop around the conical intersection yields the familiar π phase, we show that nontrivial geometric phases can also emerge in paths with zero net enclosed solid angle. Advisors: Herman Batelaan and Ilya Kravchenko
Abstract Chapter 9 discusses the rigorous incorporation of electromagnetism in quantum mechanics via minimal substitution and the inclusion of spin, which leads to the Pauli equation. The gauge invariance of this formulation is inspected more closely, which leads us to understanding quantum mechanics as a gauge theory, and on to fascinating geometric effects such as the Aharonov-Bohm effect and the discovery of geometric phases such as the Berry phase and the Aharonov-Anandan phase. To give a better context to these effects, a compact introduction to the mathematical background of differential geometry is provided, introducing concepts such as differentiable manifolds, tangent and cotangent spaces, and maps between them, as well as from their elements to the real numbers, arriving at tensors and differential forms. With these tools at hand, we first define fibre bundles before formulating the previously discussed geometric phases as well as the so-called Dirac monopole in this language
Abstract Topological and geometrical effects appear in the solution of the Schrödinger equation due to special geometrical forms of the interaction, or due to interactions which do not result from conservative forces acting on the system (see Section 1.2). A conscientious reader may point out that all these effects could be entirely explained using the Schrödinger equation only. But the geometrical phase formalism is useful because it sometimes plays a role in fundamental quantum phenomena and it shows that additional phase factors exist which are easily overlooked, making the interpretation of measured effects more mysterious than necessary. Thus, our understand-ing of quantum mechanics has deepened since the existence of geometrical phases was explicitly revealed (Shapere and Wilczek 1989). This happened due to the seminal works of Pancharatnam (1956), Berry (1984), Anandan (1992), and Bhandari (1997). It also shows that a wavefunction often carries much more information than is usually extracted in a standard experiment. A typical example is the assumption of adiabaticity, where the magnetic moment of the neutron produces (inside a slowly varying magnetic field) a dynamical phase shift proportional to the path integral ∫ B ds, but when the direction of the field varies slowly an additional, i.e. geometrical, phase also appears. The back reaction of a quantum measurement can also be described as a kind of an induced topological phase (Aharonov et al. 1998).
The smooth topology change of Berry's phase from a Dirac monopolelike configuration to a dipole configuration, when one approaches the monopole position in the parameter space, is analyzed in an exactly solvable model. A novel aspect of Berry's connection Ak is that the geometrical center of the monopolelike configuration and the origin of the Dirac string are displaced in the parameter space. Gauss's theorem ${\ensuremath{\int}}_{S}(\ensuremath{\nabla}\ifmmode\times\else\texttimes\fi{}\mathcal{A})\ifmmode\cdot\else\textperiodcentered\fi{}d\stackrel{\ensuremath{\rightarrow}}{S}={\ensuremath{\int}}_{V}\ensuremath{\nabla}\ifmmode\cdot\else\textperiodcentered\fi{}(\ensuremath{\nabla}\ifmmode\times\else\texttimes\fi{}\mathcal{A})dV=0$ for a volume V which is free of singularities shows that a combination of the monopolelike configuration and the Dirac string is effectively a dipole. The smooth topology change from a dipole to a monopole with a quantized magnetic charge ${e}_{M}=2\ensuremath{\pi}\ensuremath{\hbar}$ takes place when one regards the Dirac string as unobservable if it satisfies the Wu-Yang gauge invariance condition. In the transitional region from a dipole to a monopole, a half-monopole appears with an observable Dirac string, which is analogous to the Aharonov-Bohm phase of an electron for the magnetic flux generated by the Cooper pair condensation. The main topological features of an exactly solvable model are shown to be supported by a generic model of Berry's phase.
In this work, we study the geometric phase and the dynamics of electric and magnetic dipoles. We present your origins, some relevant works in this area as well as your results. The appearance of a geometric phase is explained when a study of quantum dynamics of the particle is made, during a complete cycle and that is subject to cyclic adiabatic processes. The present study begins with an introduction about the geometric phase, where we present examples used to illustrate it. Next, the adiabatic theorem was presented in both classical and quantum systems and a discourse on adiabatic invariants. After this, we present its final mathematical formulation and also its obtaining for a spin 1/2 particle. Soon after, we obtained the Lagrangian and its Hamiltonian, we find the quantum phase that the particle acquired in the efect Aharonov- Bohm and Aharonov - Casher. We have also seen the quantum dynamics of both electric and magnetic dipoles, where we start from the Lagrangian and study its field configurations, we reach the Ananda phase, where in the next step we obtain phases for some of the Field configurations in the Ananda phase from phase of Aharonov - Casher where we made the electric dipole moment equal to zero, as well as the He - Mckellar - Welkens phase with magnetic dipole moment equal to zero, and the Casella efect thus obtaining a particle case of the Ananda phase.