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In a three-dimensional parameter space the Berry curvature can be written in the pseudovector form = (). The tensor and pseudovector forms of the Berry curvature are related to each other through the Levi-Civita antisymmetric tensor as Ω n , μ ν = ϵ μ ν ξ Ω n , ξ {\displaystyle \Omega _{n,\mu \nu }=\epsilon _{\mu \nu \xi }\,\mathbf ...
There are several important aspects of this generalization of Berry's phase: 1) Instead of the parameter space for the original Berry phase, this Ning-Haken generalization is defined in phase space; 2) Instead of the adiabatic evolution in quantum mechanical system, the evolution of the system in phase space needs not to be adiabatic.
The Hannay angle is defined in the context of action-angle coordinates.In an initially time-invariant system, an action variable is a constant. After introducing a periodic perturbation (), the action variable becomes an adiabatic invariant, and the Hannay angle for its corresponding angle variable can be calculated according to the path integral that represents an evolution in which the ...
Symplectic manifolds arise from classical mechanics; in particular, they are a generalization of the phase space of a closed system. [1] In the same way the Hamilton equations allow one to derive the time evolution of a system from a set of differential equations, the symplectic form should allow one to obtain a vector field describing the flow of the system from the differential of a ...
This is termed the integral quantum Hall effect. These oscillations exhibit a phase shift of π, known as Berry's phase, [10] [3] which is due to the zero effective mass of carriers near the Dirac points. [48] Despite this zero effective mass, the temperature dependence of the oscillations indicates a non-zero cyclotron mass for the carriers. [10]
Trigonal bipyramidal molecular shape ax = axial ligands (on unique axis) eq = equatorial ligand (in plane perpendicular to unique axis). The Berry mechanism, or Berry pseudorotation mechanism, is a type of vibration causing molecules of certain geometries to isomerize by exchanging the two axial ligands (see the figure) for two of the equatorial ones.
Recently there was a generalization of this formula for arbitrary matrix Hamiltonians that involves a Berry phase-like term stemming from spin or other internal degrees of freedom. [9] The index distinguishes the primitive periodic orbits: the shortest period orbits of a given set of initial conditions.
In mathematics, the Chern theorem (or the Chern–Gauss–Bonnet theorem [1] [2] [3] after Shiing-Shen Chern, Carl Friedrich Gauss, and Pierre Ossian Bonnet) states that the Euler–Poincaré characteristic (a topological invariant defined as the alternating sum of the Betti numbers of a topological space) of a closed even-dimensional Riemannian manifold is equal to the integral of a certain ...