Related papers: Minimizing the linewidth of the Flux-Flow Oscillat…
The behavior of a Josephson flux-flow oscillator in the presence of both bias current and magnetic field fluctuations has been studied. To derive the equation for slow phase dynamics in the limit of small noise intensity the Poincare method…
Theoretical model for the radiation linewidth in a multi-fluxon state of a long Josephson junction is presented. Starting from the perturbed sine-Gordon model with the temperature dependent noise term, we develop a collective coordinate…
The phase dynamics of a long Josephson junction with spatially inhomogeneously distributed bias current is considered for the case of a dense soliton chain (regime of the Flux Flow oscillator). To derive the analytical solution of the…
Numerical investigation of the effects of junction geometry on the performance of the flux-flow type Josephson oscillator has been done. Using direct simulation of the sine-Gordon equation with account of RC load the spectral and power…
The flux-flow dynamics in a long Josephson junction is studied both analytically and numerically. A realistic model of the junction is considered by taking into account a nonuniform current distribution, surface losses and self-pumping…
It is shown that the generation linewidth of an auto-oscillator with a nonlinear frequency shift (i.e. an auto-oscillator in which frequency depends on the oscillation amplitude) is substantially larger than the linewidth of a conventional…
We elaborate a theoretical description of large Josephson junctions which is based on the Werthamer's microscopic tunneling theory. The model naturally incorporates coupling of electromagnetic radiation to the tunnel currents and,…
A theoretical formula of the linewidth caused by the thermal activation in a spin torque oscillator with a perpendicularly magnetized free layer and an in-plane magnetized pinned layer was developed by solving the stochastic…
Linear approximations of the AC power flow equations are of great significance for the computational efficiency of large-scale optimal power flow (OPF) problems. Put differently, the feasibility of the obtained solution is essential for…
The current-voltage and spectral characteristics of a flux flow oscillator (FFO), based on a long Josephson junction, are studied. The investigations are performed in the range of small bias currents and magnetic fields, where the FFO…
For creation of a noisy non-stationary spectrometer working in the subTHz frequency range the power and spectral characteristics of a flux flow oscillator (FFO), based on a long Josephson junction are studied. The effect of various bias…
We demonstrate a high-frequency generator operating at ~200GHz based on flipping a semifluxon in a Josephson junction of moderate normalized length. The semifluxon spontaneously appears at the $\pi$ discontinuity of the Josephson phase…
We study the behavior of the linewidth of a nano-contact based spin torque oscillator (STO) under application of a radio frequency (100 MHz) modulating current. We achieve a significant (up to 85%) reduction of the STO linewidth when it is…
This paper presents a quadratic approximation for the optimal power flow in power distributions systems. The proposed approach is based on a linearized load flow which is valid for power distribution systems including three-phase unbalanced…
Dynamics of a fluxon in a stack of inductively coupled long Josephson junctions is studied analytically and numerically. We demonstrate that the fluxon has a maximum velocity, which does not necessarily coincide with any of the…
Based on theoretical models, the dynamics of spin-torque nano-oscillators can be substantially modified by re-injecting the emitted signal to the input of the oscillator after some delay. Numerical simulations for vortex magnetic tunnel…
We present a stochastic theory of linewidths for magnetization oscillations in spin-valve structures driven by spin-polarized currents. Starting from a nonlinear oscillator model derived from spin-wave theory, we derive Langevin equations…
Given a flow network with variable suppliers and fixed consumers, the minimax flow problem consists in minimizing the maximum flow between nodes, subject to flow conservation and capacity constraints. We solve this problem over acyclic…
Linear optimal gains are computed for the subcritical two-dimensional separated boundary-layer flow past a bump. Very large optimal gain values are found, making it possible for small-amplitude noise to be strongly amplified and to…
Quantum fluctuations in a current biased Josephson junction, described in terms of the RCSJ-model, are considered. The fluctuations of the voltage and phase across the junction are assumed to be initiated by equilibrium current fluctuations…