МОДЕЛИРОВАНИЕ ОБРАЩЕНИЯ ДВИЖЕНИЯ БРОУНОВСКОЙ ЧАСТИЦЫ ПОД ДЕЙСТВИЕМ НЕРАВНОВЕСНЫХ ФЛУКТУАЦИЙ

A relevant and important question in studying the transport of nanoparticles is the possibility and methods of controlling the generated currents. One of the possibilities is to use the ratchet effect, i.e. the occurrence of directed motion as a result of the influence of nonequilibrium fluctuations of various nature when one or more symmetries in the system are broken. To implement the ratchet effect, a deterministic dichotomous process is often used, which can be modeled by two alternating states that have constant characteristics. Usually, the main factor determining the direction of motion of a Brownian motor is the spatial asymmetry of the potential profile. In certain cases, for example, for a double-well potential profile, one can relatively easily investigate the conditions for reversal of the direction of motor motion. In this paper, using the idea of Parrondo’s paradox games consisting of alternating strategies of a game that provides an average winning, we simulated the ratchet effect for a diffusion hopping model of an adiabatic Brownian motor with an asymmetric double-well on-off potential. The conditions affecting the direction of nanoparticle motion are investigated, the possibility of temperature control of the motion direction is shown, and an estimate of the generated average velocity of the Brownian motor in the adiabatic approximation is obtained. The motor functioning is simulated in terms of the game theory and the average trajectories of capital accumulation are obtained, which correspond to the trajectories of the average displacement of a Brownian particle due to the ratchet effect. For the chosen model, it is shown that, at low temperatures, a particle moves to the right in accordance with the simplest on-off ratchet model, while, at high temperatures, the motion reverses. A comparison of the simulation results with the values of the ratchet velocity obtained within the adiabatic approximation shows that this approximation becomes valid at sufficiently large values of the lifetimes of the states of the dichotomous process, and it turns out to be much more accurate in the high-temperature region than in the low-temperature one. [ABSTRACT FROM AUTHOR]