Quantum Theory Cannot Violate a Causal Inequality

Research output: Contribution to journalArticle (Academic Journal)peer-review

2 Downloads (Pure)

Abstract

Within quantum theory, we can create superpositions of different causal orders of events, and observe interference between them. This raises the question of whether quantum theory can produce results that would be impossible to replicate with any classical causal model, thereby violating a causal inequality. This would be a temporal analog of Bell inequality violation, which proves that no local hidden variable model can replicate quantum results. However, unlike the case of nonlocality, we show that quantum experiments can be simulated by a classical causal model, and therefore cannot violate a causal inequality.
Original languageEnglish
Article number110402
JournalPhysical Review Letters
Volume127
Issue number11
DOIs
Publication statusPublished - 10 Sep 2021

Bibliographical note

Funding Information:
T. P. acknowledges support from the EPSRC.

Publisher Copyright:
© 2021 American Physical Society.

Keywords

  • Spacetime topology & causal structure
  • Quantum information processing
  • Quantum foundations
  • Quantum control

Fingerprint

Dive into the research topics of 'Quantum Theory Cannot Violate a Causal Inequality'. Together they form a unique fingerprint.

Cite this