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K. Michielsen

Publications and source records attributed to K. Michielsen.

54 records · Page 3Linked to original sources

Event-by-event simulation of double-slit experiments with single photons

We present a computer simulation model that reproduces, event-by-event, the wave mechanical results of double-slit and two-beam interference experiments. The same model also simulates a one-to-one copy of a single-photon interference experiment with a Fresnel biprism (Jacques V. et al., Eur. Phys. J. D, 35 (2005) 561). The model satisfies Einstein's criterion of local causality and is solely based on experimental facts, comprising the apparatuses used in the experiment and the observation of individual detector clicks. Our results prove that it is possible to give a particle-only description of single-photon double-slit experiments.

quant-ph↗

Computer simulation of Wheeler's delayed choice experiment with photons

We present a computer simulation model of Wheeler's delayed choice experiment that is a one-to-one copy of an experiment reported recently (V. Jacques {\sl et al.}, Science 315, 966 (2007)). The model is solely based on experimental facts, satisfies Einstein's criterion of local causality and does not rely on any concept of quantum theory. Nevertheless, the simulation model reproduces the averages as obtained from the quantum theoretical description of Wheeler's delayed choice experiment. Our results prove that it is possible to give a particle-only description of Wheeler's delayed choice experiment which reproduces the averages calculated from quantum theory and which does not defy common sense.

quant-ph↗

Event-by-event simulation of quantum phenomena: Application to Einstein-Podolosky-Rosen-Bohm experiments

We review the data gathering and analysis procedure used in real Einstein-Podolsky-Rosen-Bohm experiments with photons and we illustrate the procedure by analyzing experimental data. Based on this analysis, we construct event-based computer simulation models in which every essential element in the experiment has a counterpart. The data is analyzed by counting single-particle events and two-particle coincidences, using the same procedure as in experiments. The simulation models strictly satisfy Einstein's criteria of local causality, do not rely on any concept of quantum theory or probability theory, and reproduce all results of quantum theory for a quantum system of two $S=1/2$ particles. We present a rigorous analytical treatment of these models and show that they may yield results that are in exact agreement with quantum theory. The apparent conflict with the folklore on Bell's theorem, stating that such models are not supposed to exist, is resolved. Finally, starting from the principles of probable inference, we derive the probability distributions of quantum theory of the Einstein-Podolsky-Rosen-Bohm experiment without invoking concepts of quantum theory.

quant-ph↗

Reply to Comment on "A local realist model for correlations of the singlet state"

The general conclusion of Seevinck and Larsson is that our model exploits the so-called coincidence-time loophole and produces sinusoidal (quantum-like) correlations but does not model the singlet state because it does not violate the relevant Bell inequality derived by Larsson and Gill, since in order to obtain the sinusoidal correlations the probability of coincidences in our model goes to zero. In this reply, we refute their arguments that lead to this conclusion and demonstrate that our model can reproduce results of photon and ion-trap experiments with frequencies of coincidences that are not in conflict with the observations.

quant-ph↗

Massive Parallel Quantum Computer Simulator

We describe portable software to simulate universal quantum computers on massive parallel computers. We illustrate the use of the simulation software by running various quantum algorithms on different computer architectures, such as a IBM BlueGene/L, a IBM Regatta p690+, a Hitachi SR11000/J1, a Cray X1E, a SGI Altix 3700 and clusters of PCs running Windows XP. We study the performance of the software by simulating quantum computers containing up to 36 qubits, using up to 4096 processors and up to 1 TB of memory. Our results demonstrate that the simulator exhibits nearly ideal scaling as a function of the number of processors and suggest that the simulation software described in this paper may also serve as benchmark for testing high-end parallel computers.

quant-ph↗

Efficient data processing and quantum phenomena: Single-particle systems

We study the relation between the acquisition and analysis of data and quantum theory using a probabilistic and deterministic model for photon polarizers. We introduce criteria for efficient processing of data and then use these criteria to demonstrate that efficient processing of the data contained in single events is equivalent to the observation that Malus' law holds. A strictly deterministic process that also yields Malus' law is analyzed in detail. We present a performance analysis of the probabilistic and deterministic model of the photon polarizer. The latter is an adaptive dynamical system that has primitive learning capabilities. This additional feature has recently been shown to be sufficient to perform event-by-event simulations of interference phenomena, without using concepts of wave mechanics. We illustrate this by presenting results for a system of two chained Mach-Zehnder interferometers, suggesting that systems that perform efficient data processing and have learning capability are able to exhibit behavior that is usually attributed to quantum systems only.

quant-ph↗

Simulation of Quantum Computation: A deterministic event-based approach

We demonstrate that locally connected networks of machines that have primitive learning capabilities can be used to perform a deterministic, event-based simulation of quantum computation. We present simulation results for basic quantum operations such as the Hadamard and the controlled-NOT gate, and for seven-qubit quantum networks that implement Shor's numbering factoring algorithm.

quant-ph↗

Event-based simulation of single-photon beam splitters and Mach-Zehnder interferometers

We demonstrate that networks of locally connected processing units with a primitive learning capability exhibit behavior that is usually only attributed to quantum systems. We describe networks that simulate single-photon beam-splitter and Mach-Zehnder interferometer experiments on a causal, event-by-event basis and demonstrate that the simulation results are in excellent agreement with quantum theory.

quant-ph↗

New method to simulate quantum interference using deterministic processes and application to event-based simulation of quantum computation

We demonstrate that networks of locally connected processing units with a primitive learning capability exhibit behavior that is usually only attributed to quantum systems. We describe networks that simulate single-photon beam-splitter and Mach-Zehnder interferometer experiments on a causal, event-by-event basis and demonstrate that the simulation results are in excellent agreement with quantum theory. We also show that this approach can be generalized to simulate universal quantum computers.

quant-ph↗

Deterministic event-based simulation of quantum interference

We propose and analyse simple deterministic algorithms that can be used to construct machines that have primitive learning capabilities. We demonstrate that locally connected networks of these machines can be used to perform blind classification on an event-by-event basis, without storing the information of the individual events. We also demonstrate that properly designed networks of these machines exhibit behavior that is usually only attributed to quantum systems. We present networks that simulate quantum interference on an event-by-event basis. In particular we show that by using simple geometry and the learning capabilities of the machines it becomes possible to simulate single-photon interference in a Mach-Zehnder interferometer. The interference pattern generated by the network of deterministic learning machines is in perfect agreement with the quantum theoretical result for the single-photon Mach-Zehnder interferometer. To illustrate that networks of these machines are indeed capable of simulating quantum interference we simulate, event-by-event, a setup involving two chained Mach-Zehnder interferometers. We show that also in this case the simulation results agree with quantum theory.

quant-ph↗

Microscopic origin of the adiabatic change of magnetization in molecular magnets

A microscopic model of the molecular magnet V15 is used to study mechanisms for the adiabatic change of the magnetization in time-dependent magnetic fields. Effects of the Dzyaloshinskii-Moriya interaction, the most plausible source for the energy-level repulsions that lead to adiabatic changes of the magnetization, are studied in detail. We find that the energy-level repulsions that result from this interaction exhibit a strong dependence on the direction of the applied field. We also discuss the role of magnetic anisotropy in the molecule Mn12 -acetate.

cond-mat.mtrl-sci↗

Magnetic energy-level diagrams of high-spin (Mn$_{12}$-acetate) and low-spin (V$_{15}$) molecules

The magnetic energy-level diagrams for models of the Mn12 and V15 molecule are calculated using the Lanczos method with full orthogonalization and a Chebyshev-polynomial-based projector method. The effect of the Dzyaloshinskii-Moriya interaction on the appearance of energy-level repulsions and its relevance to the observation of steps in the time-dependent magnetization data is studied. We assess the usefulness of simplified models for the description of the zero-temperature magnetization dynamics.

cond-mat.stat-mech↗

Photonic band gaps in materials with triply periodic surfaces and related tubular structures

We calculate the photonic band gap of triply periodic bicontinuous cubic structures and of tubular structures constructed from the skeletal graphs of triply periodic minimal surfaces. The effect of the symmetry and topology of the periodic dielectric structures on the existence and the characteristics of the gaps is discussed. We find that the C(I2-Y**) structure with Ia3d symmetry, a symmetry which is often seen in experimentally realized bicontinuous structures, has a photonic band gap with interesting characteristics. For a dielectric contrast of 11.9 the largest gap is approximately 20% for a volume fraction of the high dielectric material of 25%. The midgap frequency is a factor of 1.5 higher than the one for the (tubular) D and G structures.

cond-mat.mtrl-sci↗

Number Partitioning on a Quantum Computer

We present an algorithm to compute the number of solutions of the (constrained) number partitioning problem. A concrete implementation of the algorithm on an Ising-type quantum computer is given.

quant-ph↗

Morphological Image Analysis of Quantum Motion in Billiards

Morphological image analysis is applied to the time evolution of the probability distribution of a quantum particle moving in two and three-dimensional billiards. It is shown that the time-averaged Euler characteristic of the probability density provides a well defined quantity to distinguish between classically integrable and non-integrable billiards. In three dimensions the time-averaged mean breadth of the probability density may also be used for this purpose.

nlin.CD↗

Quantum Spin Dynamics and Quantum Computation

We describe a simulation method for a quantum spin model of a generic, general purpose quantum computer. The use of this quantum computer simulator is illustrated through several implementations of Grover's database search algorithm. Some preliminary results on the stability of quantum algorithms are presented.

quant-ph↗

Quantum Statistical Mechanics on a Quantum Computer

We describe a quantum algorithm to compute the density of states and thermal equilibrium properties of quantum many-body systems. We present results obtained by running this algorithm on a software implementation of a 21-qubit quantum computer for the case of an antiferromagnetic Heisenberg model on triangular lattices of different size.

quant-ph↗