Скачать или смотреть D6 S1 - Andrew Jordan - Quantum Erasing the Memory of Wigner's Friend

The Many-Worlds Interpretation of Quantum Mechanics: Current Status and Relation to Other Interpretations.
Research workshop of the Israeli Science Foundation, Tel-Aviv University, October 2022

Andrew Jordan

Quantum erasing the memory of Wigner's friend

A variation of Wigner's gedankenexperiment, introduced by Frauchiger and Renner, has lead to new debates about the self-consistency of quantum mechanics. At the core of the paradox lies the description of an observer and the object it measures as a closed system obeying the Schrödinger equation. We then propose a simple single-photon interferometric setup implementing Frauchiger and Renner's scenario, and use the derived condition to shed a new light on the assumptions leading to their paradox. From our description, we argue that the three apparently incompatible properties used to question the consistency of quantum mechanics correspond to two logically distinct contexts: either one assumes that Wigner has full control over his friends' lab, or conversely that some parts of the labs remain unaffected by Wigner's subsequent measurements. The first context may be seen as the quantum erasure of the memory of Wigner's friend.