Alvarez-Socorro A J, Clerc Marcel G, Ferré M A, Knobloch Edgar
Departamento de Física and Millennium Institute for Research in Optics, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Casilla 487-3, Santiago, Chile.
Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA.
Phys Rev E. 2019 Jun;99(6-1):062226. doi: 10.1103/PhysRevE.99.062226.
Driven dissipative many-body systems are described by differential equations for macroscopic variables which include fluctuations that account for ignored microscopic variables. Here, we investigate the effect of deterministic fluctuations, drawn from a system in a state of phase turbulence, on front dynamics. We show that despite these fluctuations a front may remain pinned, in contrast to fronts in systems with Gaussian white noise fluctuations, and explore the pinning-depinning transition. In the deterministic case, this transition is found to be robust but its location in parameter space is complex, generating a fractal-like structure. We describe this transition by deriving an equation for the front position, which takes the form of an overdamped system with a ratchet potential and chaotic forcing; this equation can, in turn, be transformed into a linear parametrically driven oscillator with a chaotically oscillating frequency. The resulting description provides an unambiguous characterization of the pinning-depinning transition in parameter space. A similar calculation for noise-driven front propagation shows that the pinning-depinning transition is washed out.
受驱耗散多体系统由宏观变量的微分方程描述，这些方程包含了用以解释被忽略微观变量的涨落。在此，我们研究源自处于相湍流状态系统的确定性涨落对前沿动力学的影响。我们表明，尽管存在这些涨落，但与具有高斯白噪声涨落的系统中的前沿不同，前沿可能会保持钉扎状态，并探索钉扎 - 解钉扎转变。在确定性情形下，发现这种转变是稳健的，但其在参数空间中的位置很复杂，会产生类似分形的结构。我们通过推导前沿位置的方程来描述这种转变，该方程具有带棘轮势和混沌驱动力的过阻尼系统的形式；反过来，这个方程又可以转化为频率混沌振荡的线性参数驱动振荡器。由此得到的描述给出了参数空间中钉扎 - 解钉扎转变的明确特征。对噪声驱动前沿传播的类似计算表明，钉扎 - 解钉扎转变被消除了。
