Quantum Distributions for the Plane Rotator. (arXiv:1807.11816v3 [quant-ph] UPDATED)

Quantum phase-space distributions (Wigner functions) for the plane rotator
are defined using wave functions expressed in both angle and angular momentum
representations, with emphasis on the quantum superposition between the Fourier
dual variable and the canonically conjugate coordinate. The standard
quantization condition for angular momentum appears as necessary for
consistency. It is shown that at finite temperature the time dependence of the
quantum wave functions may provide classical sound waves. Non-thermal quantum
entropy is associated with localization along the orbit.

Article web page: