Quantum interpretations, causality and quantum computation

Abstract

The interpretation of quantum mechanics continues to be debated, and quantum nonlocality accentuates the puzzle. Quantum interpretations can be classified broadly into two types: realist interpretations, which assert that quantum states describe objective reality (even if hidden or branching), and subjective interpretations, which treat quantum states as observer-dependent information or beliefs about the system. Here we study the implication of quantum interpretations for causal explanations of Bell nonlocal correlations, and show that a given interpretation type carries an inherent commitment to a preferred causal structure. Specifically, we find that realist interpretations entail a classical causal model, and thus require Fine-Tuning to prevent superluminal signaling, while subjective interpretations are found to entail a framework of nonclassical causal models. The implications of our results for one-way quantum computation and computation-based Bell nonlocality are studied.

8 pages, 4 figures