Using Space-Time Correlations to Identify Transient Defects

MRS Advances ◽  
2018 ◽  
Vol 3 (31) ◽  
pp. 1755-1760
Author(s):  
William Lowe ◽  
Jacob Eapen
Keyword(s):  
Dynamical Behavior ◽  
Atomistic Simulations ◽  
Dynamic Tension ◽  
Time Resolved ◽  
Scale Free ◽  
Self Organized ◽  
Time Correlations ◽  
Simulation Results ◽  
Early Radiation ◽  
Cubic Silicon Carbide

ABSTRACTAtomistic simulations are employed to investigate the dynamical behavior of atoms in cubic silicon carbide (SiC) following a 5 keV radiation knock. Specifically, we have computed the time-resolved van Hove self-correlation function, Gs(r,t), separately for the silicon and carbon sub-lattices. Our goal is to probe the early radiation damage mechanisms using a dynamical methodology. The simulation results show that the carbon atoms engage in a dynamic hopping mechanism as the system recovers from the radiation knock. The silicon atoms, however, exhibit a strikingly different behaviour: the time variation of 4πr2Gs(r,t) indicates a dynamic tension between the crystalline and disordered regions of the Si sub-lattice. The power-law tail of the 4πr2Gs(r,t) correlation for silicon atoms suggests a scale-free self-organized critical (SOC) state – a possible precursor to the collapse of the Si sub-lattice.

Structure and Photoluminescence Investigations of Self-Organized InAs/GaAs Quantum Wires

2009 ◽  
Vol 79-82 ◽  
pp. 1707-1710
Author(s):  
Ling Min Kong ◽  
Cun Xi Zhang ◽  
Rui Wang ◽  
Shi Lai Wang
Keyword(s):  
Quantum Wires ◽  
Energy Levels ◽  
Dynamical Behavior ◽  
Time Resolved ◽  
Force Microscopy ◽  
Long Wavelength ◽  
Self Organized ◽  
Atomic Force ◽  
Two Samples ◽  
Localized Excitons

Self –organized InAs quantum wires (QWRs) were fabricated on the step edges of GaAs (331)A surface by molecular beam epitaxy (MBE). The atomic force microscopy (AFM) results show that the lateral size of InAs QWRs is 90 nm while the size along the step lines increasing with the thicknesses of InAs layers, amounting to 1100nm. The height of InAs QWRs varies from 7.9nm to 13nm. Photoluminescence (PL) measurements on the two samples were explored and an obvious PL peak around 967 nm was observed at 25 K. The PL intensity decreases as the temperature increases, and it will vanish above 60 K. However, the QWR sample with thicker InAs layer emits a long emission of 1100 nm -1400 nm as the temperature rises above 50 K, and a longer emission of 1400-1600nm as the temperature approaches to 100 K. We considered that the complex photoluminescence spectra were originated from the multiple energy steps. The carrier migration among the different QWRs structures intensified with temperature, and the chance rate from the higher energy levels to the lower ones which generated a stronger emission of long wavelength. The carrier dynamics of QWR samples were measured by using time resolved PL (TRPL) spectra from 25 K to 100 K. The PL decay time in the QWR structure at longer emission was found to be independent of the temperature as T<100 K, showing a typical dynamical behavior of the localized excitons.

scholarly journals Impurity induced scale-free localization

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Linhu Li ◽  
Ching Hua Lee ◽  
Jiangbin Gong
Keyword(s):  
Boundary Conditions ◽  
Skin Effect ◽  
Reciprocal Lattice ◽  
Periodic Boundary Conditions ◽  
Open Boundary ◽  
Open Boundary Conditions ◽  
Translational Invariance ◽  
Scale Free ◽  
Special Cases ◽  
Simulation Results

AbstractNon-Hermitian systems have been shown to have a dramatic sensitivity to their boundary conditions. In particular, the non-Hermitian skin effect induces collective boundary localization upon turning off boundary coupling, a feature very distinct from that under periodic boundary conditions. Here we develop a full framework for non-Hermitian impurity physics in a non-reciprocal lattice, with periodic/open boundary conditions and even their interpolations being special cases across a whole range of boundary impurity strengths. We uncover steady states with scale-free localization along or even against the direction of non-reciprocity in various impurity strength regimes. Also present are Bloch-like states that survive albeit broken translational invariance. We further explore the co-existence of non-Hermitian skin effect and scale-free localization, where even qualitative aspects of the system’s spectrum can be extremely sensitive to impurity strength. Specific circuit setups are also proposed for experimentally detecting the scale-free accumulation, with simulation results confirming our main findings.

scholarly journals Observational evidence in favor of scale-free evolution of sunspot groups

2018 ◽  
Vol 618 ◽  
pp. A183
Author(s):  
A. Shapoval ◽  
J.-L. Le Mouël ◽  
M. Shnirman ◽  
V. Courtillot
Keyword(s):  
Weibull Distribution ◽  
Power Law ◽  
Large Range ◽  
Scale Free ◽  
Self Organized ◽  
Self Organized Criticality ◽  
Spatio Temporal ◽  
Computational Procedures ◽  
Definition Of ◽  
Sunspot Groups

Context. The hypothesis stating that the distribution of sunspot groups versus their size (φ) follows a power law in the domain of small groups was recently highlighted but rejected in favor of a Weibull distribution. Aims. In this paper we reconsider this question, and are led to the opposite conclusion. Methods. We have suggested a new definition of group size, namely the spatio-temporal “volume” (V) obtained as the sum of the observed daily areas instead of a single area associated with each group. Results. With this new definition of “size”, the width of the power-law part of the distribution φ ∼ 1/Vβ increases from 1.5 to 2.5 orders of magnitude. The exponent β is close to 1. The width of the power-law part and its exponent are stable with respect to the different catalogs and computational procedures used to reduce errors in the data. The observed distribution is not fit adequately by a Weibull distribution. Conclusions. The existence of a wide 1/V part of the distribution φ suggests that self-organized criticality underlies the generation and evolution of sunspot groups and that the mechanism responsible for it is scale-free over a large range of sizes.

scholarly journals Microcontroller Implementation, Chaos Control, Synchronization and Antisynchronization of Josephson Junction Model

2021 ◽  
Vol 1 (2) ◽  
pp. 198-208
Author(s):  
Rolande Tsapla Fotsa ◽  
André Rodrigue Tchamda ◽  
Alex Stephane Kemnang Tsafack ◽  
Sifeu Takougang Kingni
Keyword(s):  
Josephson Junction ◽  
Chaos Control ◽  
Control Method ◽  
Dynamical Behavior ◽  
Phase Portraits ◽  
Chaotic Attractors ◽  
Hurwitz Stability ◽  
Feedback Control Method ◽  
Different Shapes ◽  
Simulation Results

The microcontroller implementation, chaos control, synchronization, and antisynchronization of the nonlinear resistive-capacitive-inductive shunted Josephson junction (NRCISJJ) model are reported in this paper. The dynamical behavior of the NRCISJJ model is performed using phase portraits, and time series. The numerical simulation results reveal that the NRCISJJ model exhibits different shapes of hidden chaotic attractors by varying the parameters. The existence of different shapes of hidden chaotic attractors is confirmed by microcontroller results obtained from the microcontroller implementation of the NRCISJJ model. It is theoretically demonstrated that the two designed single controllers can suppress the hidden chaotic attractors found in the NRCISJJ model. Finally, the synchronization and antisynchronization of unidirectional coupled NRCISJJ models are studied by using the feedback control method.  Thanks to the Routh Hurwitz stability criterion, the controllers are designed in order to control chaos in JJ models and achieved synchronization and antisynchronization between coupled NRCISJJ models. Numerical simulations are shown to clarify and confirm the control, synchronization, and antisynchronization.

MONOFRACTAL AND MULTIFRACTAL SCALING ANALYSIS OF pH TIME SERIES FROM DONGTING LAKE INLET AND OUTLET

Fractals ◽  
2010 ◽  
Vol 18 (03) ◽  
pp. 309-317 ◽  
Author(s):  
ZHENG-WEN HUANG ◽  
CHUN-QIONG LIU ◽  
KAI SHI ◽  
BIN ZHANG
Keyword(s):  
Dongting Lake ◽  
Long Term Memory ◽  
Fluctuation Analysis ◽  
Scaling Analysis ◽  
Lake Water Quality ◽  
Scale Free ◽  
Self Organized ◽  
Comparison Results ◽  
Water Ph ◽  
Multifractal Scaling

The water pH series from Dongting Lake Inlet and Outlet in China are analyzed by detrended fluctuation analysis (DFA), spectral analysis and multifractal methods. The results show that these pH series are characterized by long-term memory, 1/f noise and multifractal scaling, and these characteristics have obvious difference between the Lake Inlet and Outlet. The comparison results show that monofractal (DFA exponent) and multifractal (Δα, Δf, B) parameters can be quantitative dynamical indexes reflecting the capability of anti-acidification of Dongting Lake. Furthermore, we investigate the frequency-size distribution of pH series from Dongting Lake Inlet and Outlet. Our findings suggest that water pH is an example of a self-organized criticality (SOC) process. Based on concept of self-organized ctiticality, we analysis the cause that different scale-free power-law behavior between pH series from Dongting Lake Inlet and Outlet. This work can be helpful to improvement of modeling of lake water quality.

Investigation of carrier relaxation dynamics in single CdSe/ZnSe self-organized quantum dot by time-resolved micro-photoluminescence

2001 ◽  
Vol 30 (5) ◽  
pp. 448-452 ◽  
Author(s):  
Takeshi Ota ◽  
Yasuhiro Murase ◽  
Kenzo Maehashi ◽  
Hisao Nakashima ◽  
Chikara Watatani ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Relaxation Dynamics ◽  
Time Resolved ◽  
Carrier Relaxation ◽  
Self Organized ◽  
Carrier Relaxation Dynamics

Complexity and Criticality

2020 ◽  
pp. 42-50
Author(s):  
Helmut Satz
Keyword(s):  
Complex System ◽  
Complex Systems ◽  
Critical Point ◽  
Correlation Length ◽  
Critical Behavior ◽  
Scale Free ◽  
Self Organized ◽  
Self Organized Criticality ◽  
Free Behavior

Complex systems and critical behavior in complex system are defined in terms of correlation between constituents in the medium, subject to screening by intermediate constituents. At a critical point, the correlation length diverges—as a result, one finds the scale-free behavior also observed for bird flocks. This behavior is therefore possibly a form of self-organized criticality.

scholarly journals The Formation of Social Network Assortativity: A Cultural Trait-Matching Mechanism

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Wei Wang ◽  
Xiaoming Sun ◽  
Yalan Wang ◽  
Wentian Cui
Keyword(s):  
Preferential Attachment ◽  
Scale Free Network ◽  
Selection Probability ◽  
Network Nodes ◽  
Scale Free ◽  
Cultural Trait ◽  
Free Network ◽  
Matching Mechanism ◽  
Simulation Results ◽  
Attachment Mechanism

The preferential attachment mechanism that forms scale-free network cannot display assortativity, i.e., the degree of one node is positively correlated with that of their neighbors in the network. Given the attributes of network nodes, a cultural trait-matching mechanism is further introduced in this paper. Both theoretical analysis and simulation results indicate that the higher selection probability of such mechanism, the more obvious the assortativity is shown in networks. Further, the degree of nodes presents a positive logarithm correlation with that of adjacent ones. Finally, this study discusses the theoretical and practical significances of the introduction of such a cultural trait-matching mechanism.

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