References & Citations
Quantum Physics
Title: Classical-to-quantum non-signalling boxes
(Submitted on 30 Mar 2023 (v1), last revised 25 Apr 2024 (this version, v3))
Abstract: Here we introduce the concept of classical input - quantum output (C-Q) non-signalling boxes, a generalisation of the classical input - classical output (C-C) non-signalling boxes. We argue that studying such objects leads to a better understanding of the relation between quantum nonlocality and non-locality beyond quantum mechanics. The main issue discussed in the paper is whether there exist 'genuine' C-Q boxes or all C-Q boxes can be built from objects already known, namely C-C boxes acting on pre-shared entangled quantum particles. We show that large classes of C-Q boxes are non-genuine. In particular, we show that all bi-partite C-Q boxes with outputs that are pure states are non-genuine. We also present various strategies for addressing the general problem, i.e. for multi-partite C-Q boxes which output mixed states, whose answer is still open. Finally, we show that even some very simple non-genuine C-Q boxes require large amounts of C-C nonlocal correlations in order to simulate them.
Submission history
From: Daniel Collins [view email][v1] Thu, 30 Mar 2023 10:14:51 GMT (97kb)
[v2] Tue, 11 Jul 2023 11:44:58 GMT (98kb)
[v3] Thu, 25 Apr 2024 12:47:30 GMT (196kb,D)
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