Information Constraints in Quantum Measurements and State Collapse

TL;DR

This paper investigates how quantum-mechanical information constraints during measurement influence the results, showing that they lead to stochastic outcomes consistent with quantum state collapse, regardless of apparatus decoherence.

Contribution

It demonstrates that quantum information constraints inherently cause stochastic measurement outcomes, providing a new perspective on the origin of quantum state collapse.

Findings

Measurement constraints hinder information transfer about purity of the system.

Pure and mixed states with same expectation value are indistinguishable during measurement.

Results support the view that state collapse arises from fundamental information limitations.

Abstract

Quantum-mechanical constraints on information transfer in measuring systems and their influence on measurement results studied. As the example, measurement of binary observable $S_z$ of object $\cal S$ by measuring apparatus $\cal A$ considered. It's shown that during the measurement these constraints obstacle the acquisition of information by $\cal A$, characterizing purity of $\cal S$ ensemble. Due to it, $\cal A$ can't discriminate pure and mixed $\cal S$ ensembles with the same $S_z$ expectation value. In algebraic measurement ansatz by Emch such information loss results in stochastic $S_z$ measurement outcomes for pure $\cal S$ ensemble, their probabilities obey to Born postulate, i.e. it corresponds to quantum state collapse. Account of $\cal A$ state decoherence doesn't change obtained results principally.