A Top-down versus a Bottom-up Hidden-variables Description of the Stern–Gerlach Experiment

Abstract

We employ the Stern-Gerlach experiment to highlight the basics of a minimalist, non-interpretational top-down approach to quantum foundations. Certain benefits of the here highlighted "quantum structural studies" are detected and discussed. While the top-down approach can be described without making any reference to the fundamental structure of a closed system, the hidden variables theoryá la Bohm proves to be more subtle than it is typically regarded.

Bound States as Fundamental Quantum Structures

“…In this volume, Arsenijević et al [6] discuss the challenge of deciding on physically relevant decomposition of composite systems into subsystems. Analyzing the example of an electrically neutral atom in a Stern-Gerlach apparatus, they point out that if the action of the field on the atom is indeed correctly modeled by the usual Hamiltonian interaction term inducing entanglement between the atom's center of mass and its spin, the external magnetic field of the S-G acts on the center of mass of the atom as a whole, and not individually on the electrons and nucleus.…”