English
Related papers

Related papers: A note on superposition of two unknown states usin…

200 papers

Pusey, Barrett, and Rudolph introduce a new no-go theorem for hidden-variables models of quantum theory. We make precise the class of models targeted and construct equivalent models that evade the theorem. The theorem requires assumptions…

Quantum Physics · Physics 2012-06-29 Maximilian Schlosshauer , Arthur Fine

The proof of the No-Go Theorem of unconditionally secure quantum bit commitment depends on the assumption that Alice knows every detail of the protocol, including the probability distributions associated with all the random variables…

Quantum Physics · Physics 2019-04-05 Chi-Yee Cheung

Proposed models of closed timelike curves (CTCs) have been shown to enable powerful information-processing protocols. We examine the simulation of models of CTCs both by other models of CTCs and by physical systems without access to CTCs.…

Quantum Physics · Physics 2017-02-28 Todd A. Brun , Mark M. Wilde

I argue that Deutsch's model for the behavior of systems traveling around closed timelike curves (CTCs) relies implicitly on a substantive metaphysical assumption. Deutsch is employing a version of quantum theory with a significantly…

Quantum Physics · Physics 2016-01-19 Lucas Dunlap

Quantum theory allows for the superposition of causal orders between operations, i.e., for an indefinite causal order; an implication of the principle of quantum superposition. Since a higher theory might also admit this feature, an…

Quantum Physics · Physics 2024-11-08 Kuntal Sengupta

A method to hide certain quantum states in a superposition will be proposed. Such method can be used to increase the security of a communication channel. States represent an encrypted message will disappear during data exchange. This makes…

Quantum Physics · Physics 2008-07-31 Ahmed Younes

Using a neutron double-slit setup, we construct a quantum bit commitment scheme in which time development of quantum states plays an essential role. Our scheme evades the widely accepted no-go theorem by the fact that it is neither possible…

Quantum Physics · Physics 2010-10-25 Chi-Yee Cheung

The D-CTC condition, introduced by David Deutsch as a condition to be fulfilled by analogues for processes of quantum systems in the presence of closed timelike curves, is investigated for classical statistical (non-quantum) bi-partite…

Quantum Physics · Physics 2021-10-05 Jürgen Tolksdorf , Rainer Verch

Toy models for quantum evolution in the presence of closed timelike curves (CTCs) have gained attention in the recent literature due to the strange effects they predict. The circuits that give rise to these effects appear quite abstract and…

Quantum Physics · Physics 2013-05-30 J. L. Pienaar , C. R. Myers , T. C. Ralph

The notorious Wigner's friend thought experiment (and modifications thereof) has in recent years received renewed interest especially due to new arguments that force us to question some of the fundamental assumptions of quantum theory. In…

Quantum Physics · Physics 2021-05-18 Philippe Allard Guérin , Veronika Baumann , Flavio Del Santo , Časlav Brukner

Closed timelike curves (CTCs) are trajectories in spacetime that effectively travel backwards in time: a test particle following a CTC can in principle interact with its former self in the past. CTCs appear in many solutions of Einstein's…

Incompatibility is a feature of quantum theory that sets it apart from classical theory, and the inability to clone an unknown quantum state is one of the most fundamental instances. The no-hiding theorem is another such instance that…

Quantum Physics · Physics 2025-08-12 Matthew Girling , Cristina Cirstoiu , David Jennings

Recently, Choi \emph{et al}. proposed an assumption on Mayers-Lo-Chau (MLC) no-go theorem that the state of the entire quantum system is invariable to both participants before the unveiling phase. This means that the theorem is only…

Cryptography and Security · Computer Science 2011-02-11 Qin Li , Chengqing Li , Dong-Yang Long , W. H. Chan , Chun-Hui Wu

It is a fundamental consequence of the superposition principle for quantum states that there must exist non-orthogonal states, that is states that, although different, have a non-zero overlap. This finite overlap means that there is no way…

Quantum Physics · Physics 2008-10-14 Stephen M. Barnett , Sarah Croke

The no-go theorem regarding unconditionally secure Quantum Bit Commitment protocols is a relevant result in quantum cryptography. Such result has been used to prove the impossibility of unconditional security for other protocols, such as…

Quantum Physics · Physics 2024-01-12 Silvia Onofri , Vittorio Giovannetti

It is known that probabilistically mixing an arbitrary pair of pure quantum states, one of which is entangled and the other product, in any bipartite quantum system, one always obtains an entangled state, provided the entangled state of the…

Quantum Physics · Physics 2023-04-25 Saronath Halder , Ujjwal Sen

We present a no-go theorem for the distinguishability between quantum random numbers (i.e., random numbers generated quantum mechanically) and pseudo-random numbers (i.e., random numbers generated algorithmically). The theorem states that…

In this article, we study an opposite problem of universal quantum state comparison, that is unambiguous determining whether multiple unknown quantum states from a Hilbert space are orthogonal or not. We show that no unambiguous quantum…

Quantum Physics · Physics 2015-06-05 Shengshi Pang , Shengjun Wu

Any given prescription of quantum time travel necessarily endows a Hilbert space to the chronology-violating (CV) system on the closed timelike curve (CTC). However, under the two foremost models, Deutsch's prescription (D-CTCs) and…

Quantum Physics · Physics 2025-02-10 Lachlan G. Bishop , Fabio Costa , Timothy C. Ralph

This thesis investigates the entanglement of distinguishable and indistinguishable particles, introducing a new error model for Hardy's test, experimentally verified using superconducting qubits. We address challenges in implementing…

Quantum Physics · Physics 2025-03-12 Soumya Das