Quantum Classical Transition for Mixed States: The Scaled Von Neumann Equation

Abstract

In this work, we proposed a smooth transition wave equation from a quantum to classical regime in the framework of von Neumann formalism for ensembles and then obtained an equivalent scaled equation. This led us to develop a scaled statistical theory following the well-known Wigner–Moyal approach of quantum mechanics. This scaled nonequilibrium statistical mechanics has in it all the ingredients of the classical and quantum theory described in terms of a continuous parameter displaying all the dynamical regimes in between the two extreme cases. Finally, a simple application of our scaled formalism consisting of reflection from a mirror by computing various quantities, including probability density plots, scaled trajectories, and arrival times, was analyzed.

Keywords

• Bohmian mechanics
• transition wave equation
• scaled Liouville–von Neumann equation
• scaled trajectories
• scaled Wigner–Moyal approach
• scaled Wigner distribution function