We report measurements of the photorefractive phase shift and coupling constant of several photorefractive materials. We solve the problem of beam coupling and diffraction in a material with a dynamically written grating for arbitrary input beams. These solutions are used to determine the beam coupling as a function of the photorefractive phase ø and coupling constant g when one beam is either ...

Quantum coupling is defined by comparing the evolution of an input to an output phase, where the phase is evolving on a curved pseudospherical surface. The difference given by interference obeys a single-valuedness condition since the output phase is coupling back to the input phase. We arrive at Bäcklund transforms and corresponding sine-Gordon soliton equation. The idealized resonance or feed...

We examine how the location of weak electrical coupling affects phase-locking in a pair of model fast-spiking interneurons. Each model neuron consists of a somatic compartment and a passive dendritic compartment. At relatively low frequencies, the phase-locking structure for somatic and dendritic coupling is qualitatively the same: below a critical frequency, stable synchronous and anti-phase a...

We investigate the decoherence dynamics of continuous variable entanglement as the system-environment coupling strength varies from the weak-coupling to the strong-coupling regimes. Due to the existence of localized modes in the strong-coupling regime, the system cannot approach equilibrium with its environment, which induces a nonequilibrium quantum phase transition. We analytically solve the ...

Strong gap-junctional coupling can synchronize the electrical oscillations of cells, but we show, in a theoretical model, that weak coupling can phase lock two cells 180 degrees out-of-phase. Antiphase oscillations can exist in parameter regimens where in-phase oscillations break down. Some consequences are (i) coupling two excitable cells leads to pacemaking, (ii) coupling two pacemaker cells ...

Hebb proposed that neuronal cell assemblies are critical for effective perception, cognition, and action. However, evidence for brain mechanisms that coordinate multiple coactive assemblies remains lacking. Neuronal oscillations have been suggested as one possible mechanism for cell assembly coordination. Prior studies have shown that spike timing depends upon local field potential (LFP) phase ...

We study chains of relaxation-type neural oscillators with local excitatory coupling. Phase reductions suggest that such networks typically exhibit traveling waves, but relaxation oscillators often synchronize. We examine these behaviors using the phase response and fast threshold modulation (FTM) theories, which respectively describe network behavior for infinitesimally weak and moderate coupl...

Prior studies have shown that high-frequency activity (HFA) is modulated by the phase of low-frequency activity. This phenomenon of phase-amplitude coupling (PAC) is often interpreted as reflecting phase coding of neural representations, although evidence for this link is still lacking in humans. Here, we show that PAC indeed supports phase-dependent stimulus representations for categories. Six...

— We study the synchronized/unsynchronized transition as a function of the noise intensity which appears in a system of globally coupled FitzHugh– Nagumo units under the effect of white noise. By the use of the proper definition of an order parameter, we obtain numerically the phase diagram as a function of the noise intensity and coupling constant.

This paper aims to introduce a quadrature VCO (voltage control oscillator) which applies superharmonic coupling. The presented quadrature VCO is suitable to be used, both with 2 × subharmonic mixers, as well as 4× subharmonic mixers. It would be impossible to avoid the presence of harmonics in CMOS VCO circuits. These harmonics are in general, undesirable signals which tend to accompany the des...