АДИАБАТИЧЕСКИЙ РЕЖИМ ТЕМПЕРАТУРНОГО РЕГУЛИРОВАНИЯ НАПРАВЛЕНИЯ ДВИЖЕНИЯ БРОУНОВСКОГО МОТОРА

Brownian motors are a class of nanomechanisms that generate directional motion of Brownian particles under nonequilibrium perturbations. A symmetry analysis of the factors affecting the appearance of a directed current and determining its direction indicates the dependence of the motor characteristics on the phase shift between the potential reliefs of the stationary and fluctuating components of nanoparticle potential energy. The motion of a Brownian particle located in the field of action of an extremely asymmetric stationary sawtooth potential fluctuating as a result of dichotomous effects of spatially harmonic signal is considered. Since the sawtooth potential is easily realized near a surface with a series of electrodes of a certain shape buried inside it, and the dichotomous changes of a spatially harmonic signal are easily created by laser beams, the considered motion of a nanoparticle (Brownian motor) can be realized experimentally. It is known that at sufficiently high temperatures, when the thermal energy exceeds the energy barrier of the sawtooth potential, the direction of motion is determined exclusively by the phase shift of the harmonic signal relative to the extrema of the sawtooth potential. In this article, an analytical expression for the motor average velocity has been obtained, which is valid at arbitrary temperatures, but at low frequencies of dichotomous fluctuations (adiabatic mode). An analysis of the expression has shown that there exists a critical temperature Tc below which the direction of motion loses its dependence on the magnitude of the phase shift, whereas at T > Tc the direction of motion is determined by that shift. In the region of intermediate temperatures T, for each value of the phase shift, one can indicate a temperature Ts > Tc such that at T < Ts the particle moves in one direction, while at T > Ts in the other. [ABSTRACT FROM AUTHOR]