On the reality of the quantum state once again: A no-go theorem for $\psi$-ontic models

Abstract

In this paper we show that $\psi$-ontic models, as defined by Harrigan and Spekkens (HS), cannot reproduce quantum theory. Instead of focusing on probability, we use information theoretic considerations to show that all pure states of $\psi$-ontic models must be orthogonal to each other, in clear violation of quantum mechanics. Given that (i) Pusey, Barrett and Rudolph (PBR) previously showed that $\psi$-epistemic models, as defined by HS, also contradict quantum mechanics, and (ii) the HS categorization is exhausted by these two types of models, we conclude that the HS categorization itself is problematic as it leaves no space for models that can reproduce quantum theory.

6 pages + 1 page mathematical appendix, 2 figures. Accepted by Foundations of Physics

References in corpus (5)

• Is the quantum state real? An extended review of $\psi$-ontology theorems
• Implications of the Pusey-Barrett-Rudolph quantum no-go theorem
• How ψ-epistemic models fail at explaining the indistinguishability of quantum states
• How Real are Quantum States in $\psi$-ontic Models?
• Relational Quantum Mechanics and the PBR Theorem: A Peaceful Coexistence

Cited by in corpus (1)

• Information versus Physicality: On the Nature of the Wavefunctions of Quantum Mechanics