arXiv:1103.0774 · Physical Review A

Comment on “Information flow of quantum states interacting with closed timelike curves”

Waldemar Kłobus, Andrzej Grudka, Antoni Wójcik

Published Nov 23, 2011• 2 citations

Abstract

We show that recent results on the interaction of causality-respecting particles with particles on closed timelike curves derived in [Phys. Rev. A 82, 062330 (2010)] depend on ambiguous assumptions about the form of the state which is inputted into the proposed equivalent circuit. Choosing a different form of this state leads to an opposite conclusion on the power of closed timelike curves.

DOI: 10.1103/physreva.84.056301

Related papers

Reply to “Comment on ‘Information flow of quantum states interacting with closed timelike curves’”

Timothy C. Ralph, Casey R. Myers

We respond to the comment by K\l{}obus et al. [Phys. Rev. A 84, 056301 (2011)] by emphasizing that the equivalent circuit, once constructed, obeys the standard rules of quantum mechanics---hence there is no ambiguity in how to choose initial states in our model. We discuss the distinction between correlated ensembles produced nonlocally via measurements on entangled states and those produced via local preparation.

arXiv:1112.0820Physical Review ANov 23, 20114 citations

Problems with modelling closed timelike curves as post-selected teleportation

Timothy C. Ralph

In this comment on S.Lloyd, et al, Phys.Rev.Lett. 106, 040403 (2011), we show that modelling closed timelike curves (CTCs) as post-selected teleportation allows signalling to past times before the creation of the CTC and allows information paradoxes to form.

arXiv:1107.4675Jul 23, 20115 citations

Quantum no-go theorems in causality respecting systems in the presence of closed timelike curves: Tweaking the Deutsch condition

Asutosh Kumar, Indranil Chakrabarty, Arun Kumar Pati +2 more

Quantum no-go theorems in causality respecting systems in the presence of closed timelike curves: Tweaking the Deutsch condition, Kumar, Asutosh, Chakrabarty, Indranil, Pati, Arun Kumar, Sen(De), Aditi, Sen, Ujjwal

arXiv:1511.08560Europhysics Letters (EPL)Jun 6, 20183 citations

Information flow of quantum states interacting with closed timelike curves

Timothy C. Ralph, Casey R. Myers

Recently, the quantum information processing power of closed timelike curves has been discussed. Because the most widely accepted model for quantum closed timelike curve interactions contains ambiguities, different authors have been able to reach radically different conclusions as to the power of such interactions. By tracing the information flow through such systems we are able to derive equivalent circuits with unique solutions, thus allowing an objective decision between the alternatives to be made. We conclude that closed timelike curves, if they exist and are well described by these simple models, would be a powerful resource for quantum information processing.

arXiv:1003.1987Physical Review ADec 29, 201037 citations

Comment on “Single-particle entanglement”

Aurélien Drezet

We show that contrarily to what it is claimed in Phys. Rev. A 72, 064306 (2005) entanglement is not necessary for explaining experimental results associated with the ``single particle-vacuum'' state $\ensuremath{\mid}\ensuremath{\psi}⟩\ensuremath{\sim}\ensuremath{\mid}0{⟩}_{A}\ensuremath{\mid}1{⟩}_{B}+\ensuremath{\mid}1{⟩}_{A}\ensuremath{\mid}0{⟩}_{B}$.

Physical Review AAug 21, 200630 citations

Reply to “Comment on ‘Past of a quantum particle’ ”

Lev Vaidman A

Misinterpretation in the preceding Comment of my recent analysis of the past of a photon is corrected. There is nothing in this analysis which is ``contrary to the usual quantum expectations'' but, nevertheless, it does provide ``further understanding and interpretation of the system considered.'' In particular, it indicates that the common sense argument used in the Comment should be abandoned.

Physical Review AOct 29, 201347 citations