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Related papers: Quantum mechanical Universal constructor

200 papers

In a recent preprint [1] Jeffrey Bub presents a discussion of neo-Bohrian interpretations of quantum mechanics, and also of von Neumann's work on infinite tensor products [2]. He rightfully writes that this work provides a theoretical…

Quantum Physics · Physics 2025-12-30 Philippe Grangier

The quantum computer is supposed to process information by applying unitary transformations to the complex amplitudes defining the state of N qubits. A useful machine needing N=1000 or more, the number of continuous parameters describing…

Quantum Physics · Physics 2014-09-23 M. I. Dyakonov

A non-relativistic quantum mechanical theory is proposed that describes the universe as a continuum of worlds whose mutual interference gives rise to quantum phenomena. A logical framework is introduced to properly deal with propositions…

Quantum Physics · Physics 2015-08-18 Kim Joris Boström

We compare how the impossibility of a universal work extractor from coherence arises from different approaches to quantum thermodynamics: an explicit protocol accounting for all relevant quantum resources, and axiomatic,…

Quantum Physics · Physics 2024-04-12 Samuel Plesnik , Maria Violaris

It is shown that in two-state quantum theory, a generic quantum state can be described by a non-computable real number. In terms of this, the criterion for measurement outcome is simply and deterministically defined. This demonstration is…

Quantum Physics · Physics 2007-05-23 T. N. Palmer

A quantum simulator is a device engineered to reproduce the properties of an ideal quantum model. It allows the study of quantum systems that cannot be efficiently simulated on classical computers. While a universal quantum computer is also…

Quantum Physics · Physics 2011-12-16 J. Casanova , C. Sabin , J. Leon , I. L. Egusquiza , R. Gerritsma , C. F. Roos , J. J. Garcia-Ripoll , E. Solano

A consistent physical theory of quantum mechanics can be built on a complex Hamiltonian that is not Hermitian but instead satisfies the physical condition of space-time reflection symmetry (PT symmetry). Thus, there are infinitely many new…

High Energy Physics - Theory · Physics 2009-11-10 Carl M. Bender , Dorje C. Brody , Hugh F. Jones

On classical phase spaces admitting just one complex-differentiable structure, there is no indeterminacy in the choice of the creation operators that create quanta out of a given vacuum. In these cases the notion of a quantum is universal,…

Quantum Physics · Physics 2009-11-10 J. M. Isidro

Quantum theory brings into question the compatibility of the twin desiderata of exact knowability of the present state of the physical world and perfect predictability of its future states. Bohr's coordination-causality complementarity…

Quantum Physics · Physics 2026-03-27 Philip Goyal

We investigate a new class of quantum cloning machines that equally duplicate all real states in a Hilbert space of arbitrary dimension. By using the no-signaling condition, namely that cloning cannot make superluminal communication…

Quantum Physics · Physics 2009-11-10 Patrick Navez , Nicolas J. Cerf

The paper puts into discussion the concept of universality, in particular for structures not of the power of Turing computability. The question arises if for such structures a universal structure of the same kind exists or not. For that the…

Computational Complexity · Computer Science 2009-06-23 Manfred Kudlek

The wide-spread opinion is that original quantum mechanics is a reversible theory, but this statement is only true for undecomposed systems, that are those systems which sub-systems are out of consideration. Taking sub-systems into account,…

Quantum Physics · Physics 2022-11-24 Wolfgang Muschik

In classical computation, a problem can be solved in multiple steps where calculated results of each step can be copied and used repeatedly. While in quantum computation, it is difficult to realize a similar multi-step computation process…

Quantum Physics · Physics 2023-01-19 Hefeng Wang , Sixia Yu , Hua Xiang

We pose the question whether the asymptotic equivalence between quantum cloning and quantum state estimation, valid at the single-clone level, still holds when all clones are examined globally. We conjecture that the answer is affirmative…

Quantum Physics · Physics 2014-11-12 G. Chiribella , Y. Yang

We establish the best possible approximation to a perfect quantum cloning machine which produces two clones out of a single input. We analyze both universal and state-dependent cloners. The maximal fidelity of cloning is shown to be 5/6 for…

Quantum Physics · Physics 2009-10-30 D. Bruss , D. P. DiVincenzo , A. Ekert , C. A. Fuchs , C. Macchiavello , J. A. Smolin

Based on a number of experimentally verified physical observations, it is argued that the standard principles of quantum mechanics should be applied to the Universe as a whole. Thus, a paradigm is proposed in which the entire Universe is…

General Relativity and Quantum Cosmology · Physics 2007-05-23 J. S. Eakins

We introduce the concept of cloning for classes of observables and classify cloning machines for qubit systems according to the number of parameters needed to describe the class under investigation. A no-cloning theorem for observables is…

Quantum Physics · Physics 2009-11-11 Alessandro Ferraro , Matteo Galbiati , Matteo G. A. Paris

We prove that there is no algorithm to tell whether an arbitrarily constructed Quantum Turing Machine has same time steps for different branches of computation. We, hence, can not avoid the notion of halting to be probabilistic in Quantum…

Quantum Physics · Physics 2007-05-23 Takayuki Miyadera , Masanori Ohya

In this work we initiate the question of whether quantum devices can provide us with an almost perfect source of classical randomness, and more generally, suffice for classical cryptographic tasks, such as encryption. Indeed, it is well…

Quantum Physics · Physics 2007-05-23 Yevgeniy Dodis , Renato Renner

This paper focuses on a constructive treatment of the mathematical formalism of quantum theory and a possible role of constructivist philosophy in resolving the foundational problems of quantum mechanics, particularly, the controversy over…

Quantum Physics · Physics 2016-05-25 Arkady Bolotin