Quantum and semi-classical aspects of confined systems with variable mass

TL;DR

This paper investigates the quantization of classical systems with position-dependent mass confined to a bounded interval, using covariant integral quantization to produce well-defined operators and explore quantum and semi-classical effects.

Contribution

It introduces a phase space regularization method for PDM systems that avoids self-adjoint extension issues and naturally yields semi-classical models with quantum effects.

Findings

Well-defined quantum operators for PDM systems without self-adjoint extensions.

Emergence of a vector potential in the quantum and semi-classical models.

Semi-classical models retain quantum effects through Planck's constant.

Abstract

We explore the quantization of classical models with position-dependent mass (PDM) terms constrained to a bounded interval in the canonical position. This is achieved through the Weyl-Heisenberg covariant integral quantization by properly choosing a regularizing function $\Pi(q,p)$ on the phase space that smooths the discontinuities present in the classical model. We thus obtain well-defined operators without requiring the construction of self-adjoint extensions. Simultaneously, the quantization mechanism leads naturally to a semi-classical system, that is, a classical-like model with a well-defined Hamiltonian structure in which the effects of the Planck's constant are not negligible. Interestingly, for a non-separable function $\Pi(q,p)$, a purely quantum minimal-coupling term arises in the form of a vector potential for both the quantum and semi-classical models.