Communication complexity and the reality of the wave-function

Abstract

In this review, we discuss a relation between quantum communication complexity and a long-standing debate in quantum foundation concerning the interpretation of the quantum state. Is the quantum state a physical element of reality as originally interpreted by Schrodinger? Or is it an abstract mathematical object containing statistical information about the outcome of measurements as interpreted by Born? Although these questions sound philosophical and pointless, they can be made precise in the framework of what we call classical theories of quantum processes, which are a reword of quantum phenomena in the language of classical probability theory. In 2012, Pusey, Barrett and Rudolph (PBR) proved, under an assumption of preparation independence, a theorem supporting the original interpretation of Schrodinger in the classical framework. Recently, we showed that these questions are related to a practical problem in quantum communication complexity, namely, quantifying the minimal amount of classical communication required in the classical simulation of a two-party quantum communication process. In particular, we argued that the statement of the PBR theorem can be proved if the classical communication cost of simulating the communication of n qubits grows more than exponentially in 'n'. Our argument is based on an assumption that we call probability equipartition property. This property is somehow weaker than the preparation independence property used in the PBR theorem, as the former can be justified by the latter and the asymptotic equipartition property of independent stochastic sources. The equipartition property is a general and natural hypothesis that can be assumed even if the preparation independence hypothesis is dropped. In this review, we further develop our argument into the form of a theorem.

References in corpus (8)

• The Communication Cost of Simulating Bell Correlations
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• Implications of the Pusey-Barrett-Rudolph quantum no-go theorem
• Exponential complexity and ontological theories of quantum mechanics
• Epistemic view of quantum states and communication complexity of quantum channels
• State space dimensionality in short memory hidden variable theories
• Necessary and sufficient optimality conditions for classical simulations of quantum communication processes
• Compressing the hidden variable space of a qubit

Cited by in corpus (3)

• How Real are Quantum States in $\psi$-ontic Models?
• Reality, Causality, and Quantum Theory
• Quantum Entanglement in Time