تقرير
Quantum Interactions with Closed Timelike Curves and Superluminal Signaling
| العنوان: | Quantum Interactions with Closed Timelike Curves and Superluminal Signaling |
|---|---|
| المؤلفون: | Bub, Jeffrey, Stairs, Allen |
| المصدر: | Physical Review A 89, 022311 (2014) |
| سنة النشر: | 2013 |
| المجموعة: | Quantum Physics |
| مصطلحات موضوعية: | Quantum Physics |
| الوصف: | There is now a significant body of results on quantum interactions with closed timelike curves (CTCs) in the quantum information literature, for both the Deutsch model of CTC interactions (D-CTCs) and the projective model (P-CTCs). As a consequence, there is a prima facie argument exploiting entanglement that CTC interactions would enable superluminal and, indeed, effectively instantaneous signaling. In cases of spacelike separation between the sender of a signal and the receiver, whether a receiver measures the local part of an entangled state or a disentangled state to access the signal can depend on the reference frame. We propose a consistency condition that gives priority to either an entangled perspective or a disentangled perspective in spacelike separated scenarios. For D-CTC interactions, the consistency condition gives priority to frames of reference in which the state is disentangled, while for P-CTC interactions the condition selects the entangled state. Using the consistency condition, we show that there is a procedure that allows Alice to signal to Bob in the past via relayed superluminal communications between spacelike separated Alice and Clio, and spacelike separated Clio and Bob. This opens the door to time travel paradoxes in the classical domain. Ralph (arXiv:1107.4675) first pointed this out for P-CTCs, but we show that Ralph's procedure for a 'radio to the past' is flawed. Since both D-CTCs and P-CTCs allow classical information to be sent around a spacetime loop, it follows from a result by Aaronson and Watrous (Proc.Roy.Soc.A, 465:631-647 (2009)) for CTC-enhanced classical computation that a quantum computer with access to P-CTCs would have the power of PSPACE, equivalent to a D-CTC-enhanced quantum computer. Comment: 8 pages, 3 figures. Revised version of paper presented at conference 'Quantum Mechanics Seen Through Closed Timelike Curves,' Fondation des Treilles, France, June 24--28, 2013. Version 4 corrects some typos, adds reference to paper by C.H. Bennett et al. Selected by editors of Physical Review as Editor's Choice |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1103/PhysRevA.89.022311 |
| URL الوصول: | http://arxiv.org/abs/1309.4751 |
| رقم الأكسشن: | edsarx.1309.4751 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1103/PhysRevA.89.022311 |
|---|