منابع مشابه
Generating All Wigner Functions
In the context of phase-space quantization, matrix elements and observables result from integration of c-number functions over phase space, with Wigner functions serving as the quasi-probability measure. The complete sets of Wigner functions necessary to expand all phase-space functions include off-diagonal Wigner functions, which may appear technically involved. Nevertheless, it is shown here ...
متن کاملWigner Functions with Boundaries
We consider a general Wigner function for a particle confined to a finite interval and subject to Dirichlet boundary conditions. We derive the boundary corrections to the ”star-genvalue” equation and to the time evolution equation. These corrections can be cast in the form of a boundary potential contributing to the total Hamiltonian. Moreover, in this context, it is the boundary potential that...
متن کاملEntropy and wigner functions
The properties of an alternative definition of quantum entropy, based on Wigner functions, are discussed. Such a definition emerges naturally from the Wigner representation of quantum mechanics, and can easily quantify the amount of entanglement of a quantum state. It is shown that smoothing of the Wigner function induces an increase in entropy. This fact is used to derive some simple rules to ...
متن کاملSemiclassical propagation of Wigner functions.
We present a comprehensive study of semiclassical phase-space propagation in the Wigner representation, emphasizing numerical applications, in particular as an initial-value representation. Two semiclassical approximation schemes are discussed. The propagator of the Wigner function based on van Vleck's approximation replaces the Liouville propagator by a quantum spot with an oscillatory pattern...
متن کاملWigner Functions versus WKB-Methods
We consider the Cauchy-problem for a class of scalar linear dispersive equations with rapidly oscillating initial data. The problem of high-frequency asymptotics of such models is reviewed, in particular we highlight the difficulties in crossing caustics when using (time-dependent) WKB-methods, leading to ”multi-valued” solutions of Hamilton-Jacobi equations. Using Wigner measures we present an...
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ژورنال
عنوان ژورنال: Physical Review A
سال: 2007
ISSN: 1050-2947,1094-1622
DOI: 10.1103/physreva.75.052107