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1.
We consider the escape of the particles multi-state noise. It is shown that, the noise can make over fluctuating potential barrier for a system only driven by a the particles escape over the fluctuating potential barrier in some circumstances; but in other circumstances, it can not. If the noise can make the particle escape over the fluctuating potential barrier, the mean first passage time (MFPT) can display the phenomenon of multi-resonant-activation. For this phenomenon, there are two kinds of resonant activation to appear. One is resonant activation for the MFPTs as the function of the flipping rates of the fluctuating potential barrier; the other is that for the MFPTs as the functions of the transition rates of the multi-state noise. 相似文献
2.
In this paper, we introduce a noise which is composed of multiplication of two dichotomous noises, and derive the probability density and the statistical properties of this noise. The obtained results can help study the resonant activation phenomenon, the phenomenon of stochastic resonance, the transport of particles, and the nonequilibrium (phase) transition for the systems driven by this noise. 相似文献
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4.
D. Martila R. Mankin R. Tammelo A. Sauga E. Reiter 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,54(3):375-383
The influence of noise-flatness on overdamped motion of
Brownian particles in a 1D periodic system with a simple sawtooth
potential subjected to both unbiased thermal noise and
three-level telegraph noise is considered. The exact formula for
the stationary probability flux (current) is presented. The
phenomenon of multiple current reversals and some topological
properties of the hypersurface of zero current in the parameter
space of noises are investigated and illustrated by phase
diagrams. The conditions for the existence of four current
reversals versus the switching rate of nonequilibrium noise are
given. An alternative interpretation of the results in terms of
cross-correlation between two dichotomous noises is presented. 相似文献
5.
A linear system driven by correlated asymmetric dichotomous noises and periodic signal was investigated in the overdamped
case. The exact expressions of output signal amplitude and signal-to-noise ratio (SNR) of the system were derived. By means
of numerical calculations, we found that: (i) At some fixed multiplicative noise intensities, the output signal amplitude
with frequency exhibits the structure of a weak peak, even no peak as the dichotomous noise is asymmetric; (ii) In the case
of asymmetric dichotomous noise, the signal frequency can cause non-monotonous behavior of the output signal amplitude with
respect to multiplicative noise intensity; (iii) The curve of SNR with frequency has a weak peak and a trough in the case
of symmetric dichotomous noise, but no peak with asymmetric; (iv) Whether the multiplicative noise is symmetric or asymmetric,
the noise can enhance response of the system; (v) The SNR increases with the correlation strength between the two noises decreasing.
In addition, the plane of multiplicative noise intensity versus noise symmetric parameter was plotted. 相似文献
6.
The transport of a symmetric periodic potential driven by a static bias and correlated noises is investigated for both the over-damped case and the under-damped case. By both theoretical approximation and numerical simulations, we study steady current of an over-damped Brownian particle moving in the potential. It is shown that the symmetric periodic potential driven by a static bias and the correlated noises is simultaneously able to exhibit directional transport, a single current reversal, as well as a double current reversal. For the under-damped case, we examine the dynamic at various inertial strengths by direct simulations of the stochastic differential equations. We specially focus on the influence of inertial term in the particle dynamics for the noise induced, directed current. Different directions of the steady current is found for different masses of the particles, thus an efficient scheme to separate the Brownian particles according to their mass is suggested. 相似文献
7.
Could one single dichotomous noise cause resonant activation for exit time over potential barrier?
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This paper studies the mean first passage time (or exit time, or escape time) over the non-fluctuating potential harrier for a system driven only by a dichotomous noise. It finds that the dichotomous noise can make the particles escape over the potential barrier, in some circumstances; but in other circumstances, it can not. In the case that the particles escape over the potential harrier, a resonant activation phenomenon for the mean first passage time over the potential barrier is obtained. 相似文献
8.
《Physics letters. A》2006,359(6):573-576
The escape for the mean first passage time (MFPT) over the fluctuating potential barrier for system only driven by a dichotomous noise is investigated. It is found that, in some circumstances, the dichotomous noise can induce the resonant activation for the MFPT over the fluctuating potential barrier, but in other circumstances, it cannot. There are two resonant activations for the MFPT. One is the MFPT as a function of the flipping rate of the fluctuating potential barrier, the other is the MFPT as a function of the transition rate of the dichotomous noise. 相似文献
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10.
LI Jing-Hui 《理论物理通讯》2008,50(5):1159-1164
In this paper, an electric system with two dichotomous resistors
is investigated. It is shown that this system can display two
stochastic resonances, which are the amplitude of the periodic
response as the functions of the two dichotomous resistors
strengthes respectively. In the limits of Gaussian white noise and
shot white noise (i.e., the two noises are both Gaussian white
noise or shot white noise), no phenomena of resonance appear. By
further study, we find that when the system is with three or more
multiplicative telegraphic noises, there are three or more
stochastic resonances. 相似文献
11.
以往的研究大多考虑线性谐振子模型受频率涨落噪声的影响, 而当布朗粒子处于具有吸附能力的复杂环境时, 粒子质量也存在随机涨落. 因此, 本文研究具有质量及频率涨落两项噪声的二阶欠阻尼线性谐振子模型的随机共振现象. 利用Shapiro-Loginov公式和Laplace变换, 推导了系统响应一阶稳态矩及稳态响应振幅的解析表达式. 并根据稳态响应振幅的解析表达式, 建立了稳态响应振幅关于质量涨落噪声及频率涨落噪声各自的噪声强度能够诱导随机共振现象产生的充分必要条件. 仿真实验表明, 当系统参数满足本文所给出的充分必要条件要求时, 系统稳态响应振幅关于噪声强度的变化曲线具有明显的共振峰, 即此选定参数组合能够诱导系统产生随机共振现象. 相似文献
12.
B. Spagnolo A. Dubkov 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,50(1-2):299-303
The one-dimensional overdamped Brownian motion in a symmetric
periodic potential modulated by external time-reversible noise is
analyzed. The calculation of the effective diffusion coefficient
is reduced to the mean first passage time problem. We derive
general equations to calculate the effective diffusion coefficient
of Brownian particles moving in arbitrary supersymmetric potential
modulated by: (i) an external white Gaussian noise and (ii) a
Markovian dichotomous noise. For both cases the exact expressions
for the effective diffusion coefficient are derived. We obtain
acceleration of diffusion in comparison with the free diffusion
case for fast fluctuating potentials with arbitrary profile and
for sawtooth potential in case (ii). In this case the parameter
region where this effect can be observed is given. We obtain also
a finite net diffusion in the absence of thermal noise. For
rectangular potential the diffusion slows down, for all parameters
of noise and of potential, in comparison with the case when
particles diffuse freely. 相似文献
13.
Effect of inertial mass on a linear system driven by dichotomous noise and a periodic signal
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A linear system driven by dichotomous noise and a periodic signal is investigated in the underdamped case. The exact expressions of output signal amplitude and signal-to-noise ratio (SNR) of the system are derived. By means of numerical calculation, the results indicate that (i) at some fixed noise intensities, the output signal amplitude with inertial mass exhibits the structure of a single peak and single valley, or even two peaks if the dichotomous noise is asymmetric; (ii) in the case of asymmetric dichotomous noise, the inertial mass can cause non-monotonic behaviour of the output signal amplitude with respect to noise intensity; (iii) the curve of SNR versus inertial mass displays a maximum in the case of asymmetric dichotomous noise, i.e., a resonance-like phenomenon, while it decreases monotonically in the case of symmetric dichotomous noise; (iv) if the noise is symmetric, the inertial mass can induce stochastic resonance in the system. 相似文献
14.
Current transport and mass separation for an asymmetric fluctuation system with correlated noises
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We discuss the transport of an underdamped particle driven by an external fluctuation force in a spatially periodic asymmetric potential with correlated noises. The corresponding mathematical model is established. The movement of the steady current of an underdamped particle is presented by the method of the numerical simulation. It is indicated that the value of the current may be negative, zero, or positive. The external fluctuation force and correlated noises can effect the current direction. Under the appropriate parameters, the correlated noises intensity may even raise a reversal of the current.Besides, we have noticed a phenomenon that particles with different weight have different directions during movement by the impact of the correlated noises and external fluctuation force. Therefore, the Brownian particles can be effectively separated according to their masses. 相似文献
15.
In this paper, we discuss the motion of a Brownian particle in a double-well potential driven by a periodic force in terms of energies delivered by the periodic and the noise forces and energy dissipated into the viscous environment. It is shown that, while the power delivered by the periodic force to the Brownian particle is controlled by the strength of the noise, the power delivered by the noise itself is independent of the amplitude and frequency of the periodic force. The implications of this result for the mechanism of stochastic resonance in an equilibrium system is that it is not energy from the noise force which enhances a small periodic force, but rather an increase of energy delivered by the periodic force, regulated by the strength of the noise. We further re-evaluate the frequency dependence of stochastic resonance in terms of energetic terms including efficiency. 相似文献
16.
The fractional Langevin equation is derived from the generalized Langevin equation driven by the additive fractional Gaussian noise. We investigate the stochastic resonance (SR) phenomenon in the underdamped linear fractional Langevin equation under the external periodic force and multiplicative symmetric dichotomous noise. Applying the Shapiro-Loginov formula and the Laplace transform technique, we obtain the exact expressions of the amplitude and signal-to-noise ratio (SNR) of the system. By studying the impacts of the driving frequency and the noise parameters, we find the non-monotonic behaviors of the output amplitude and SNR. The results indicate that the bona fide SR, conventional SR and the wide sense of SR phenomena occur in the proposed linear fractional system. 相似文献
17.
Noise-Induced Phase Transition: Zero-Dimensional Brownian Particles Varying between Ergodicity and Nonergodicity
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We study in phase space a zero-dimensional system of Brownian particles which move in a periodic potential and subject to an internal time derivative Ornstein-Uhlenbeck noise. To resolve the Fokker-Planck equation in such a case, we propose an approximate analytical method. The theoretical predictions exhibit a second order noise-induced nonequilibrium phase transition, which is confirmed by numerical simulation results. The phase transition brings the system from an ergodicity to a nonergodicity phase as the potential barrier height decreases. 相似文献
18.
研究在周期信号和高斯白噪声共同作用下过阻尼搓板势系统的随机共振.由于用直接模拟法研究随机系统所用时间较多,考虑用半解析的方法对系统的随机共振现象进行研究.在弱周期信号极限下,结合线性响应理论和扰动展开法提出一种计算系统线性响应的矩方法.在此基础上,利用Floquet理论和非扰动展开法将矩方法扩展到系统非线性响应的计算.通过直接数值模拟结果和矩方法所得结果的比较展示了矩方法的有效性并采用均方差作为量化指标给出其适用的参数范围.研究结果表明,以系统的功率谱放大因子作为量化指标,发现在适当的参数条件下,系统的共振曲线有一个单峰出现,说明过阻尼搓板势系统存在随机共振现象.而且在一定范围内调节偏置参数时,共振曲线的峰值随偏置参数的增大而增大;在调节驱动幅值时,随机共振效应随驱动幅值的增大而增强. 相似文献
19.
We study transport properties of a system composed of Brownian particles immersed in a periodic potential. Interaction among the Brownian particles is treated perturbationally in a framework of a generalized Fokker-Planck equation, which due to the interaction contains a renormalized periodic potential and an extra mean field term. We solve the kinetic equation numerically and discuss effects of the (repulsive) interaction on dynamic response functions and transport coefficients. 相似文献
20.
Effect of inertia mass on the stochastic resonance driven by a multiplicative dichotomous noise
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A stochastic system driven by dichotomous noise and periodic signal is investigated in the under-damped case.The exact expressions of output signal amplitude and signal-to-noise ratio(SNR) of the system are derived.Numerical results indicate that the inertial mass greatly affects the output signal amplitude and the SNR.Regardless of whether the noise is symmetric or asymmetric,the inertial mass can influence the phenomenon of stochastic resonance(SR) of the system,leading to two types of resonance phenomenon:one is coherence-resonance-like of the SNR with inertial mass,the other is the SR of the SNR with noise intensity. 相似文献