English
Related papers

Related papers: Some relations between quantum Turing machines and…

200 papers

A geometric construction of the arrival time in conventional quantum mechanics is presented. It is based on a careful mathematical analysis of different quantization procedures for classical observables as functions of positions and…

Quantum Physics · Physics 2023-06-14 Jerzy Kijowski

We consider the computational model of the Queue Automaton. An old result is that the deterministic queue automaton is equally expressive as the Turing machine. We introduced the Reactive Turing Machine, enhancing the Turing machine with a…

Formal Languages and Automata Theory · Computer Science 2025-02-13 Jos C. M. Baeten , Bas Luttik

We study characteristics of quantum evolution which can be called curvature and torsion. The curvature shows a deviation of the state vector in quantum evolution from the geodesic line. The torsion shows a deviation of state vector from the…

Quantum Physics · Physics 2017-04-03 H. P. Laba , V. M. Tkachuk

Given a Hamiltonian $H$ on a Hilbert space $\mathcal H$ it is shown that, under the assumption that $\sigma(H)=\sigma_{ac}(H)=R^+$, there exist unique positive operators $T_F$ and $T_B$ registering the Schr\"odinger time evolution generated…

Mathematical Physics · Physics 2007-06-13 Y. Strauss

We study the problem of computing the probability for the time-of-arrival of a quantum particle at a given spatial position. We consider a solution to this problem based on the spectral decomposition of the particle's (Heisenberg) state…

Quantum Physics · Physics 2009-10-30 Norbert Grot , Carlo Rovelli , Ranjeet S. Tate

The time evolution operator (Schr\"odinger functional) of quantum field theory can be expressed in terms of first quantised particles moving on the orbifold $S^1/Z_2$. We give a graphical derivation of this that generalises to second…

High Energy Physics - Theory · Physics 2009-11-10 Anton Ilderton , Paul Mansfield

We investigate the class of physical theories with the same local structure as quantum theory, but a potentially different global structure. It has previously been shown that any bipartite correlations generated by such a theory must be…

Quantum Physics · Physics 2013-05-30 Gonzalo de la Torre , Lluis Masanes , Anthony J. Short , Markus P. Mueller

Probabilistic cellular automata with deterministic updating are quantum systems. We employ the quantum formalism for an investigation of random probabilistic cellular automata, which start with a probability distribution over initial…

Quantum Physics · Physics 2024-05-17 A. Kreuzkamp , C. Wetterich

The conflict between quantum theory and the theory of relativity is exemplified in their treatment of time. We examine the ways in which their conceptions differ, and describe a semiclassical clock model combining elements of both theories.…

Quantum Physics · Physics 2019-01-23 Maximilian P. E. Lock , Ivette Fuentes

Each scheme of state reconstruction comes down to parametrize the state of a quantum system by expectation values or probabilities directly measurable in an experiment. It is argued that the time evolution of these quantities provides an…

Quantum Physics · Physics 2014-11-18 Stefan Weigert

We investigate the quantum recurrence phenomena in periodically driven systems. We calculate the classical period and the quantum recurrence time and develop their interdependence. We further predict the behavior of the recurrence phenomena…

Quantum Physics · Physics 2007-05-23 Farhan Saif

Quantum machine learning may permit to realize more efficient machine learning calculations with near-term quantum devices. Among the diverse quantum machine learning paradigms which are currently being considered, quantum memristors are…

Quantum Physics · Physics 2024-12-30 Lucas Lamata

We first rewrite the perturbation expansion of the time evolution operator [An Min Wang, quant-ph/0611216] in a form as concise as possible. Then we derive out the perturbation expansion of the time-dependent complete Green operator and…

Quantum Physics · Physics 2007-05-23 An Min Wang

The local conservation of a physical quantity whose distribution changes with time is mathematically described by the continuity equation. The corresponding time parameter, however, is defined with respect to an idealized classical clock.…

Chemical Physics · Physics 2018-11-21 Axel Schild

The effect of the inevitable coupling to external degrees of freedom of a quantum computer are examined. It is found that for quantum calculations (in which the maintenance of coherence over a large number of states is important), not only…

High Energy Physics - Theory · Physics 2009-10-28 W. G. Unruh

The ``evolving constants'' method of defining the quantum dynamics of time-reparametrization-invariant theories is investigated for a particular implementation of parametrized non-relativistic quantum mechanics (PNRQM). The wide range of…

General Relativity and Quantum Cosmology · Physics 2009-10-28 James B. Hartle

Characterising the intelligence of biological organisms is challenging. This work considers intelligent algorithms developed evolutionarily within neural systems. Mathematical analyses unveil a natural equivalence between canonical neural…

Neurons and Cognition · Quantitative Biology 2025-01-06 Takuya Isomura

In this paper we unveil some features of a discrete-time quantum walk on the line whose coin depends on the temporal variable. After considering the most general form of the unitary coin operator, we focus on the role played by the two…

Quantum Physics · Physics 2014-12-08 Miquel Montero

This work uses a simple quantum computer model to discuss the randomness of bit strings originated from integer sequences. The considered quantum computer model has three elements: a processing unit responsible for a mathematical operation,…

Quantum Physics · Physics 2015-05-05 R. V. Ramos

We present a number of new physical systems that may be addressed using methods of time dependent transformation. A recap of results available for two-state systems is given, with particular emphasis on the AC stark effect. We give some…

Quantum Physics · Physics 2023-06-05 Peter Morrison