2020/09/08 by A. K. Pan
Computer Science · Medicine · Physics and Astronomy · #Biofield Effects and Biophysics #Coherence (philosophical gambling strategy) #Computer science #Interference (communication) #Physics #Quantum #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum mechanics #Statistical physics #Theoretical physics #Weak measurement #quant-ph
paper · pdf · doi:10.1103/physreva.102.032206
published as Phys. Rev. A, 102, 032206 (2020) · Published version
openalex publication_date 2020/09/08 · arxiv created 2020/12/27 · arxiv updated 2020/12/29 · openalex created_date 2021/01/05 · openalex updated_date 2026/08/05
Macrorealism is a classical world view asserting that the properties of macro-objects exist independently and irrespective of observation. One practical approach to test this view in quantum theory is to observe the quantum coherence for a macro-object in an interference experiment. An elegant and conceptually appealing approach for testing the notion of macrorealism in quantum theory is through the violation of Leggett-Garg inequality. However, a conclusive Leggett-Garg test hinges on how the noninvasive measurability criteria are guaranteed in an experiment and remains a debated issue to date. In this work, we connect the practical and the conceptual approaches for testing the macrorealism through the weak value. We argue that whenever a quantum effect is observed in an interference experiment there is an existence of anomalous weak value. Further, we demonstrate that whenever such weak value exists, one obtains the violation of a Leggett-Garg inequality in any interference experiment. Since in a path-only interference experiment effectively no prior measurement is performed, the Leggett-Garg test of macrorealism presented here is without assuming the noninvasive measurability. We provide a rigorous discussion about the assumptions involved in the Leggett-Garg scenario and how our scheme fits into it. Further, we provide a simple argument about the macrorealistic understanding of our results by using the recently developed approach involving quasiprobability.