Searcharxiv⌕ Search

arXiv subjects

Alexander Yu. Vlasov

Publications and source records attributed to Alexander Yu. Vlasov.

64 records · Page 4Linked to original sources
arXiv2000

Algebra, Logic and Qubits: Quantum Abacus

The canonical anticommutation relations (CAR) for fermion systems can be represented by finite-dimensional matrix algebra, but it is impossible for canonical commutation relations (CCR) for bosons. After description of more simple case with representation of CAR and (bounded) quantum computational networks via Clifford algebras in the paper are discussed CCR. For representation of the algebra it is not enough to use quantum networks with fixed number of qubits and it is more convenient to consider Turing machine with essential operation of appending new cells for description of infinite tape in finite terms --- it has straightforward generalization for quantum case, but for CCR it is necessary to work with symmetrized version of the quantum Turing machine. The system is called here quantum abacus due to understanding analogy with the ancient counting devices (abacus).

quant-ph↗
arXiv2000

Von Neumann Quantum Logic vs. Classical von Neumann Architecture?

The name of John von Neumann is common both in quantum mechanics and computer science. Are they really two absolutely unconnected areas? Many works devoted to quantum computations and communications are serious argument to suggest about existence of such a relation, but it is impossible to touch the new and active theme in a short review. In the paper are described the structures and models of linear algebra and just due to their generality it is possible to use universal description of very different areas as quantum mechanics and theory of Bayesian image analysis, associative memory, neural networks, fuzzy logic.

cs.OH↗
arXiv1999

Error Correction with Euclidean Qubits

In classical case there is simplest method of error correction with using three equal bits instead of one. In the paper is shown, how the scheme fails for quantum error correction with complex vector spaces of usual quantum mechanics, but works in real and quaternionic cases. It is discussed also, how to implement the three qubits scheme with using encoding of quaternionic qubit by Majorana spinor. Necessary concepts and formulae from area of quantum error corrections are closely introduced and proved.

quant-ph↗
arXiv1999

Quantum Theory of Computation and Relativistic Physics

In the e-print is discussed a few steps to introducing of "vocabulary" of relativistic physics in quantum theory of information and computation (QTI&C). The behavior of a few simple quantum systems those are used as models in QTI&C is tested by usual relativistic tools (transformation properties of wave vectors, etc.). Massless and charged massive particles with spin 1/2 are considered. Field theory is also discussed briefly.

quant-ph↗
arXiv1999

Quantum Gates and Clifford Algebras

Clifford algebras are used for definition of spinors. Because of using spin-1/2 systems as an adequate model of quantum bit, a relation of the algebras with quantum information science has physical reasons. But there are simple mathematical properties of the algebras those also justifies such applications. First, any complex Clifford algebra with 2n generators, Cl(2n,C), has representation as algebra of all 2^n x 2^n complex matrices and so includes unitary matrix of any quantum n-gate. An arbitrary element of whole algebra corresponds to general form of linear complex transformation. The last property is also useful because linear operators are not necessary should be unitary if they used for description of restriction of some unitary operator to subspace. The second advantage is simple algebraic structure of Cl(2n) that can be expressed via tenzor product of standard "building units" and similar with behavior of composite quantum systems. The compact notation with 2n generators also can be used in software for modeling of simple quantum circuits by modern conventional computers.

quant-ph↗
arXiv1999

Universal Object Oriented Languages and Computer Algebra

The universal object oriented languages made programming more simple and efficient. In the article is considered possibilities of using similar methods in computer algebra. A clear and powerful universal language is useful if particular problem was not implemented in standard software packages like REDUCE, MATHEMATICA, etc. and if the using of internal programming languages of the packages looks not very efficient. Functional languages like LISP had some advantages and traditions for algebraic and symbolic manipulations. Functional and object oriented programming are not incompatible ones. An extension of the model of an object for manipulation with pure functions and algebraic expressions is considered.

cs.PL↗
arXiv1999

Object Oriented and Functional Programming for Symbolic Manipulation

The advantages of mixed approach with using different kinds of programming techniques for symbolic manipulation are discussed. The main purpose of approach offered is merge the methods of object oriented programming that convenient for presentation data and algorithms for user with advantages of functional languages for data manipulation, internal presentation, and portability of software.

cs.SC↗
arXiv1998

Analogue Quantum Computers for Data Analysis

Analogue computers use continuous properties of physical system for modeling. In the paper is described possibility of modeling by analogue quantum computers for some model of data analysis. It is analogue associative memory and a formal neural network. A particularity of the models is combination of continuous internal processes with discrete set of output states. The modeling of the system by classical analogue computers was offered long times ago, but now it is not very effectively in comparison with modern digital computers. The application of quantum analogue modelling looks quite possible for modern level of technology and it may be more effective than digital one, because number of element may be about Avogadro number (N=6.0E23).

quant-ph↗
arXiv1997

Quantum Computations and Images Recognition

The using of quantum parallelism is often connected with consideration of quantum system with huge dimension of space of states. The n-qubit register can be described by complex vector with 2^n components (it belongs to n'th tensor power of qubit spaces). For example, for algorithm of factorization of numbers by quantum computer n can be about a few hundreds for some realistic applications for cryptography. The applications described further are used some other properties of quantum systems and they do not demand such huge number of states. The term "images recognition" is used here for some broad class of problems. For example, we have a set of some objects V_i and function of "likelihood": F(V,W) < F(V,V) = 1 If we have some "noisy" or "distorted" image W, we can say that recognition of W is V_i, if F(W,V_i) is near 1 for some V_i.

quant-ph↗