From qubits and actions to the Pauli-Schroedinger equation

TL;DR

This paper demonstrates that a simple model combining a qubit state and an action can derive the Pauli-Schroedinger equation, linking quantum dynamics to information-theoretic principles and internal degrees of freedom.

Contribution

It introduces a novel derivation of the Pauli-Schroedinger equation from classical or quantum bits plus an action, connecting quantum evolution to information and internal degrees of freedom.

Findings

Derivation of the Pauli-Schroedinger equation from qubit and action

Particle motion described by wavefunction due to internal qubit state

Suggests internal degrees of freedom influence classical particle dynamics

Abstract

Here I show that a classical or quantum bit state plus one simple operation, an action, are sufficient ingredients to derive a quantum dynamical equation that rules the sequential changes of the state. Then, by assuming that a freely moving massive particle is the qubit carrier, it is found that both, the particle position in physical space and the qubit state, change in time according to the Pauli-Schroedinger equation. So, this approach suggests the following conjecture: because it carries one qubit of information the particle motion has its description enslaved by the very existence of the internal degree of freedom. It is compelled to be no more described classically but by a wavefunction. I also briefly discuss the Dirac equation in terms of qubits.