We investigate the dynamical behavior of quantum discord with weak measurement under various environments. We find that the quantum discord closely relates to the interaction between qubits, measurement strength and the correlation rate between environments of qubits. The interaction results in oscillation of quantum discord and avoids quantum discord sudden death for certain initial states. The stronger the interaction is, more intense the oscillation is. The increase of measurement strength will lead to the decrease of quantum discord. The correlation rate also affects the quantum correlation significantly. Stronger correlation is favor to improve the quantum correlation between qubits. Not only the amplitude of quantum discord is increased, but also the time for zero quantum discord is greatly delayed.
High-frequencyoscillations... Time–frequency distributions. On the left side, the full 20–1000 Hz range is displayed for three exemplary subjects. The two graphs per subject show the ERG and VEP activity, respectively. The high-frequencyoscillations appear as a distinct area which in most cases is around or above 100 Hz. The flash was given at t=0. Those parts of the time–frequency diagram which would be contaminated by edge effects are displayed in white. Their spread is due to the inevitable frequency-dependent finite time resolution, which also causes the spurious pre-stimulus activity at low frequencies. The white rectangles in the diagrams mark the regions of interest, which are shown enlarged on the right side for all 7 subjects. The arrows link the high-frequency maxima of ERG and VEP. Most subjects produced activity around or above 100 Hz in both VEP and ERG. However, only in one subject (S1) the frequencies matched. Asterisks indicate the significance levels of frequency differences in standard notation, based on a sequential Bonferroni adjustment. No significance value could be obtained for subject S3.
Oscillation bands form an arithmetic progression on the logarithmic scale. For each band the frequency (Hz) or period ranges are shown together with their commonly used names.
... Brain oscillators... Alpha, gamma and theta oscillations
Contributors:Mina Amiri, Jean-Marc Lina, Francesca Pizzo, Jean Gotman
Examples of a spike without HFOs (left) and a spike with HFOs (right), as defined with the Analytic Morse wavelet in the time–frequency domain.
... High FrequencyOscillations... Parameter selection for the Analytic Morse Wavelet; top: time–frequency presentation for different values of n (m=40), bottom: raw signal and filtered signal (80–250Hz). Blue lines represent HFO interval marked visually.
... Examples of detection errors. Left: HFO without isolated blob but having oscillation in the raw signal. Right: HFO without visible oscillation in the raw signal but representing an isolated peak. Blue lines show the HFO interval marked by reviewers.
Contributors:L.C. Fai, J.T. Diffo, M.E. Ateuafack, M. Tchoffo, G.C. Fouokeng
Time evolution of the LZ transition probability in the diabatic basis of a two-level system in the presence of a low-frequency Gaussian coloured noise. (a) Low-frequency noise limit (Eq. (20)). (b) All frequency limits (Eq. (24)). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)
... Qubit... shows the curves for the low-frequency Dichotomous noise where (a) corresponds to low-frequency Dichotomous noise (Eq. (28)) and (b), all frequency limits (Eq. (31)).
(A) Comparison of the frequency of oscillations during oblique, pure horizontal and pure vertical saccades. Number of observations is plotted on y-axis, while x-axis represents bins of oscillationfrequency. Each data point represents the number of observations in a given frequency bin. Black trace suggests oblique saccade, Gray traces with circular symbols are horizontal saccades and triangular symbols represent vertical saccade. Dashed lines depict median oscillationfrequency. (B) Comparison of frequency oblique saccade oscillations with the frequency of orthogonal saccadic oscillations during pure horizontal and vertical saccades. Each data point depicts one subject. Black data points are comparison with pure horizontal saccade, gray data points are comparison with vertical saccade. Dashed gray line is an equality line. (C) Comparison of the amplitude of the sinusoidal modulation of oblique, horizontal, and vertical saccade trajectories. Number of samples is plotted on y-axis, while x-axis represents the amplitude bins. Each data point depicts number of observations in a given bin of the histogram. Black trace shows oblique saccade, Gray trace with circuit symbol is a horizontal saccade and the triangular symbol is a vertical saccade. Dashed lines represent median values.
... An example of horizontal, vertical, and oblique saccade from one healthy subject. The left column depicts horizontal saccade; central column vertical, and right column is oblique saccade. Panels A, B and C illustrate eye position vector plotted along y-axis. Panels D, E and F represent eye velocity vector plotted along y-axis while ordinate in panels G, H and I illustrate eye acceleration. In each panel, x-axis represents corresponding time. Arrows in panels C, F, I show oscillations in oblique saccade trajectory.