QUANTUM TRAJECTORY CALCULATIONS FOR BIPOLAR WAVEPACKET DYNAMICS IN ONE DIMENSION: SYNTHETIC SINGLE-WAVEPACKET PROPAGATION

2010 ◽  
Vol 09 (04) ◽  
pp. 711-734 ◽  
Author(s):  
KISAM PARK ◽  
BILL POIRIER
Keyword(s):  
Initial Conditions ◽  
Technical Difficulty ◽  
One Dimension ◽  
Quantum Trajectory ◽  
One Dimensional ◽  
Trajectory Calculations ◽  
Wave Packet Dynamics ◽  
Wavepacket Dynamics ◽  
Trajectory Method ◽  
The Given

In a previous paper [Park K, Poirier B, Parlant G, J Chem Phys129:194112, 2008], a synthetic quantum trajectory method (QTM) was successfully implemented for wave-packet dynamics in a one-dimensional (1D) symmetric Eckart barrier system, utilizing a "double-wavepacket" version of the bipolar decomposition, ψ = ψ+ + ψ- = (ψ1+ + ψ2+) + (ψ1- + ψ2-), to avoid a technical difficulty involving negligible initial ψ- density. In this paper, we develop a new synthetic algorithm which overcomes this difficulty directly, utilizing the original "single-wavepacket" version of the bipolar decomposition, ψ =ψ+ + ψ-, and also show that the initial propagation of ψ- is mainly governed by probability transfer from ψ+, rather than by the given initial conditions for ψ-. The new algorithm makes it possible to apply the synthetic bipolar QTM to asymptotically asymmetric as well as symmetric potential systems. Successful application results for both symmetric and asymmetric Eckart barrier systems in 1D are presented.

Quantum trajectory calculations for bipolar wavepacket dynamics in one dimension

2008 ◽  
Vol 129 (19) ◽  
pp. 194112 ◽  
Author(s):  
Kisam Park ◽  
Bill Poirier ◽  
Gérard Parlant
Keyword(s):  
One Dimension ◽  
Quantum Trajectory ◽  
Trajectory Calculations ◽  
Wavepacket Dynamics

scholarly journals A general formulation of the quasiclassical trajectory method for reduced-dimensionality reaction dynamics calculations

2018 ◽  
Vol 20 (19) ◽  
pp. 13224-13240 ◽  
Author(s):  
Tibor Nagy ◽  
Anna Vikár ◽  
György Lendvay
Keyword(s):  
Initial Conditions ◽  
Reaction Dynamics ◽  
Black Box ◽  
Reduced Dimensionality ◽  
Trajectory Calculations ◽  
Internal Coordinates ◽  
Trajectory Method

A black-box formalism for generating initial conditions and following trajectories in reduced-dimensionality quasiclassical trajectory calculations using arbitrary internal coordinates.

PARALLEL ADAPTIVE QUANTUM TRAJECTORY METHOD FOR WAVEPACKET SIMULATIONS

2005 ◽  
Vol 15 (04) ◽  
pp. 415-422 ◽  
Author(s):  
RICOLINDO L. CARIÑO ◽  
IOANA BANICESCU ◽  
RAVI K. VADAPALLI ◽  
CHARLES A. WEATHERFORD ◽  
JIANPING ZHU
Keyword(s):  
Weighted Least Squares ◽  
Free Particle ◽  
Computation Time ◽  
Quantum Trajectory ◽  
Loop Scheduling ◽  
Load Imbalance ◽  
Wavepacket Dynamics ◽  
Trajectory Method ◽  
Linux Cluster ◽  
Computationally Intensive

Time-dependent wavepackets are widely used to model various phenomena in physics. One approach in simulating the wavepacket dynamics is the quantum trajectory method (QTM). Based on the hydrodynamic formulation of quantum mechanics, the QTM represents the wavepacket by an unstructured set of pseudoparticles whose trajectories are coupled by the quantum potential. The governing equations for the pseudoparticle trajectories are solved using a computationally-intensive moving weighted least squares (MWLS) algorithm, and the trajectories can be computed in parallel. This paper contributes a strategy for improving the performance of wavepacket simulations using the QTM. Specifically, adaptivity is incorporated into the MWLS algorithm, and loop scheduling techniques are employed to dynamically load balance the parallel computation of the trajectories. The adaptive MWLS algorithm reduces the amount of computations without sacrificing accuracy, while adaptive loop scheduling addresses the load imbalance introduced by the algorithm and the runtime system. Results of experiments on a Linux cluster are presented to confirm that the adaptive MWLS reduces the trajectory computation time by up to 24%, and adaptive loop scheduling achieves parallel efficiencies of up to 85% when simulating a free particle.

scholarly journals Assessing a Linear Nanosystem's Limiting Reliability from its Components

2008 ◽  
Vol 45 (03) ◽  
pp. 879-887 ◽  
Author(s):  
Nader Ebrahimi
Keyword(s):  
Present State ◽  
Size Range ◽  
Two Dimensions ◽  
The Other ◽  
One Dimension ◽  
Present Moment ◽  
One Dimensional ◽  
The One ◽  
Fixed Moment ◽  
Nanosized Systems

Nanosystems are devices that are in the size range of a billionth of a meter (1 x 10-9) and therefore are built necessarily from individual atoms. The one-dimensional nanosystems or linear nanosystems cover all the nanosized systems which possess one dimension that exceeds the other two dimensions, i.e. extension over one dimension is predominant over the other two dimensions. Here only two of the dimensions have to be on the nanoscale (less than 100 nanometers). In this paper we consider the structural relationship between a linear nanosystem and its atoms acting as components of the nanosystem. Using such information, we then assess the nanosystem's limiting reliability which is, of course, probabilistic in nature. We consider the linear nanosystem at a fixed moment of time, say the present moment, and we assume that the present state of the linear nanosystem depends only on the present states of its atoms.

scholarly journals EXACT SOLUTION OF AN IRREVERSIBLE ONE-DIMENSIONAL MODEL WITH FULLY BIASED SPIN EXCHANGES

1996 ◽  
Vol 10 (25) ◽  
pp. 3451-3459 ◽  
Author(s):  
ANTÓNIO M.R. CADILHE ◽  
VLADIMIR PRIVMAN
Keyword(s):  
Exact Solution ◽  
Domain Wall ◽  
Nearest Neighbor ◽  
Spin Exchange ◽  
Initial Conditions ◽  
Strong Dependence ◽  
Zero Temperature ◽  
Dimensional Model ◽  
One Dimensional ◽  
Temperature Dynamics

We introduce a model with conserved dynamics, where nearest neighbor pairs of spins ↑↓ (↓↑) can exchange to assume the configuration ↓↑ (↑↓), with rate β(α), through energy decreasing moves only. We report exact solution for the case when one of the rates, α or β, is zero. The irreversibility of such zero-temperature dynamics results in strong dependence on the initial conditions. Domain wall arguments suggest that for more general, finite-temperature models with steady states the dynamical critical exponent for the anisotropic spin exchange is different from the isotropic value.

scholarly journals BLOCK CIPHERS ON THE BASIS OF REVERSIBLE CELLULAR AUTOMATA

2020 ◽  
Vol 10 (1) ◽  
pp. 8-11
Author(s):  
Yuliya Tanasyuk ◽  
Petro Burdeinyi
Keyword(s):  
Cellular Automata ◽  
Block Cipher ◽  
Key Generation ◽  
One Dimensional ◽  
C Programming Language ◽  
C Programming ◽  
Shared Secret ◽  
Reversible Cellular Automata ◽  
The Given ◽  
First Time

The given paper is devoted to the software development of block cipher based on reversible one-dimensional cellular automata and the study of its statistical properties. The software implementation of the proposed encryption algorithm is performed in C# programming language in Visual Studio 2017. The paper presents specially designed approach for key generation. To ensure desired cryptographic stability, the shared secret parameters can be adjusted to contain information needed for creating substitution tables, defining reversible rules, and hiding final data. For the first time, it is suggested to create substitution tables based on iterations of a cellular automaton that is initialized by the key data.

scholarly journals Complex Transmission Eigenvalues in One Dimension

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Yalin Zhang ◽  
Yanling Wang ◽  
Guoliang Shi ◽  
Shizhong Liao
Keyword(s):  
Index Of Refraction ◽  
One Dimension ◽  
Transmission Eigenvalues ◽  
One Dimensional ◽  
Complex Eigenvalues ◽  
Complex Transmission

We consider all of the transmission eigenvalues for one-dimensional media. We give some conditions under which complex eigenvalues exist. In the case when the index of refraction is constant, it is shown that all the transmission eigenvalues are real if and only if the index of refraction is an odd number or reciprocal of an odd number.

Dimensionality and Construct Validity of a Video-Based, Objective Personality Test for the Assessment of Willingness to Take Risks in Road Traffic

2005 ◽  
Vol 97 (1) ◽  
pp. 309-320 ◽  
Author(s):  
Martin E. Arendasy ◽  
Andreas Hergovich ◽  
Markus Sommer ◽  
Bettina Bognar
Keyword(s):  
Construct Validity ◽  
Personality Trait ◽  
Road Traffic ◽  
Personality Test ◽  
Traffic Situation ◽  
One Dimensional ◽  
First Results ◽  
The One ◽  
The Given ◽  
Homeostasis Theory

The study at hand reports first results about the dimensionality and construct validity of a newly developed objective, video-based personality test, which assesses the willingness to take risks in traffic situations. On the basis of the theory of risk homeostasis developed by Wilde, different traffic situations with varying amounts of objective danger were filmed. These situations mainly consisted of situations with passing maneuvers and speed choice or traffic situations at intersections. Each of these traffic situations describes an action which should be carried out. The videos of the traffic situations are presented twice. Before the first presentation, a short written explanation of the preceding traffic situation and a situation-contingent reaction is provided. The respondents are allowed to obtain an overview of the given situations during the first presentation of each traffic situation. During the second presentation the respondents are asked to indicate at which point the action that is contingent on the described situation will become too dangerous to carry out. Latencies for items were recorded as a measure for the magnitude of the person's subjectively accepted willingness to take risks in the sense of the risk homeostasis theory by Wilde. In a study with 243 people with different education and sex, the one-dimensionality of the test corresponding to the latency model by Scheiblechner was investigated. Analysis indicated that the new measure assesses a one-dimensional latent personality trait which can be interpreted as subjectively accepted amount of risk (target risk value). First indicators for the construct validity of the test are given by a significant correlation with the construct-related secondary scale, adventurousness of the Eysenck Personality Profiler with, at the same time, nonsignificant correlations to the two secondary scales, extroversion and emotional stability, that are not linked to the construct.

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