Discrete–continuous and classical–quantum

2007 ◽  
Vol 17 (2) ◽  
pp. 177-183 ◽  
Author(s):  
THIERRY PAUL

We present a discussion concerning the opposition between discreteness and the continuum in quantum mechanics. In particular, it is shown that this duality was not restricted to the early days of the theory, but remains current, and features different aspects of discretisation. In particular, the discreteness of quantum mechanics is key for quantum information and quantum computation. We propose a conclusion involving a concept of completeness linking discreteness and the continuum.

2003 ◽  
Vol 1 (2) ◽  
pp. 120-121
Author(s):  
Neeraj Sinha

One of the most promising scieniifc of East century was the Computers. Computers of initial days were of very large size consisting vacuum tubes ond valves. This has taken over by sernicor-,ductor and transistors which were 0' smaller size and more efficient. The rapid growth in the semiconductor industry hos led to the present form computer on our desktop. This hos initiated the questions about the ultimate limit of this development. AS size Of computer chip is decreasing, if has been predicted by Moor's law that within next twenty year, the size Of a sing bit will be of the order of a single atom. Physical laws governing the atomic phenomena, such cs quantum mechanics, are very different from macroscopic laws. so the computers operating on atomic level will not be Same cs pæsent days computers. This possibility has openee c completely new field of Quantum Computation.


2004 ◽  
Vol 213 ◽  
pp. 237-244
Author(s):  
Paul Davies

The race to build a quantum computer has led to a radical re-evaluation of the concept of information. In this paper I conjecture that life, defined as an information processing and replicating system, may be exploiting the considerable efficiency advantages offered by quantum computation, and that quantum information processing may dramatically shorten the odds for life originating from a random chemical soup. The plausibility of this conjecture rests, however, on life somehow circumventing the decoherence effects of the environment. I offer some speculations on ways in which this might happen.


Author(s):  
Majid Beshkar

The QBIT theory is an attempt toward solving the problem of consciousness based on empirical evidence provided by various scientific disciplines including Quantum mechanics, Biology, Information theory, and Thermodynamics. This theory formulates the problem of consciousness in the following four questions: (1) What is the nature of qualia? (2) How are qualia generated? (3) Why are qualia subjective? (4) Why does a quale have a particular quality or meaning?In sum, the QBIT theory proposes that (1) when certainty of an observer about an event exceeds a certain level, the observer becomes conscious of that event; (2) consciousness requires Maxwell demon-assisted quantum computation; (3) a quale is a dense pack of meaningful quantum information encoded in maximally entangled pure states; (4) a quale is generated when robustness of an internal representation exceeds a certain threshold; (5) the quality or meaning of a quale is determined by a process of information compression via the matching and unification of patterns; and (6) subjectivity of consciousness is due to the fact that maximally entangled pure states are private and unshareable.


2021 ◽  
Author(s):  
Vasil Dinev Penchev

The paper interprets the concept “operator in the separable complex Hilbert space” (particalry, “Hermitian operator” as “quantity” is defined in the “classical” quantum mechanics) by that of “quantum information”. As far as wave function is the characteristic function of the probability (density) distribution for all possible values of a certain quantity to be measured, the definition of quantity in quantum mechanics means any unitary change of the probability (density) distribution. It can be represented as a particular case of “unitary” qubits. The converse interpretation of any qubits as referring to a certain physical quantity implies its generalization to non-Hermitian operators, thus neither unitary, nor conserving energy. Their physical sense, speaking loosely, consists in exchanging temporal moments therefore being implemented out of the space-time “screen”. “Dark matter” and “dark energy” can be explained by the same generalization of “quantity” to non-Hermitian operators only secondarily projected on the pseudo-Riemannian space-time “screen” of general relativity according to Einstein's “Mach’s principle” and his field equation.


Entropy ◽  
2021 ◽  
Vol 23 (1) ◽  
pp. 114
Author(s):  
Michael Silberstein ◽  
William Mark Stuckey ◽  
Timothy McDevitt

Our account provides a local, realist and fully non-causal principle explanation for EPR correlations, contextuality, no-signalling, and the Tsirelson bound. Indeed, the account herein is fully consistent with the causal structure of Minkowski spacetime. We argue that retrocausal accounts of quantum mechanics are problematic precisely because they do not fully transcend the assumption that causal or constructive explanation must always be fundamental. Unlike retrocausal accounts, our principle explanation is a complete rejection of Reichenbach’s Principle. Furthermore, we will argue that the basis for our principle account of quantum mechanics is the physical principle sought by quantum information theorists for their reconstructions of quantum mechanics. Finally, we explain why our account is both fully realist and psi-epistemic.


2007 ◽  
Vol 05 (06) ◽  
pp. 913-921
Author(s):  
JÁNOS A. BERGOU

This two-volume book is a great addition to the growing number of books devoted to the field. It is very clearly written by classroom professionals, always with the students in mind. The tutorial presentation is supplemented with a number of exercises whose solutions are also given at the end of each volume. The first volume can serve as a textbook for a one semester introductory course in quantum computation and quantum information. The second volume is more technical and brings the reader to the level of the current literature. It is useful for the specialist, can serve as a textbook for a more advanced course, or has its place as a reference book. In summary, I can highly recommend this book to anyone interested in this field.


2016 ◽  
Vol 66 (2) ◽  
Author(s):  
Maria Luisa Dalla Chiara ◽  
Roberto Giuntini ◽  
Roberto Leporini ◽  
Giuseppe Sergioli

AbstractQuantum computational logics represent a logical abstraction from the circuit-theory in quantum computation. In these logics formulas are supposed to denote pieces of quantum information (qubits, quregisters or mixtures of quregisters), while logical connectives correspond to (quantum logical) gates that transform quantum information in a reversible way. The characteristic holistic features of the quantum theoretic formalism (which play an essential role in entanglement-phenomena) can be used in order to develop a


2001 ◽  
Vol 15 (27) ◽  
pp. 1259-1264 ◽  
Author(s):  
M. ANDRECUT ◽  
M. K. ALI

The preparation of a quantum register in an arbitrary superposed quantum state is an important operation for quantum computation and quantum information processing. Here, we present an efficient algorithm which requires a polynomial number of elementary operations for initializing the amplitude distribution of a quantum register.


2020 ◽  
Author(s):  
Vasil Dinev Penchev

If the concept of “free will” is reduced to that of “choice” all physical world share the latter quality. Anyway the “free will” can be distinguished from the “choice”: The “free will” involves implicitly a certain goal, and the choice is only the mean, by which the aim can be achieved or not by the one who determines the target. Thus, for example, an electron has always a choice but not free will unlike a human possessing both. Consequently, and paradoxically, the determinism of classical physics is more subjective and more anthropomorphic than the indeterminism of quantum mechanics for the former presupposes certain deterministic goal implicitly following the model of human freewill behavior. Quantum mechanics introduces the choice in the fundament of physical world involving a generalized case of choice, which can be called “subjectless”: There is certain choice, which originates from the transition of the future into the past. Thus that kind of choice is shared of all existing and does not need any subject: It can be considered as a low of nature. There are a few theorems in quantum mechanics directly relevant to the topic: two of them are called “free will theorems” by their authors (Conway and Kochen 2006; 2009). Any quantum system either a human or an electron or whatever else has always a choice: Its behavior is not predetermined by its past. This is a physical law. It implies that a form of information, the quantum information underlies all existing for the unit of the quantity of information is an elementary choice: either a bit or a quantum bit (qubit).


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