Figure 1

Schematic sketch of various types of Brownian gyrators acting as heat engines. The black dot represents the Brownian particle, moving in the $x_1\mathrm{\text{−}}{x}_2$ plane. The contour lines indicate a typical parabolic potential (1) with principal axes $y_1$ and $y_2$. (a)–(c) illustrate different realizations of the two heat baths. (a) Both heat baths act on the charged particle by way of blackbody radiation at different temperatures $T_1$ and $T_2$, irradiating along the $x_1$ and $x_2$ axes, respectively. The dissipation mechanism is provided by radiation damping into the vacuum. (b) “Electrical heat baths,” realized by two resistors at different temperatures $T_1$ and $T_2$, coupled to the charged particle by means of two plate condensers. Each of them transfers the random voltage fluctuations of one resistor to the particle along a preferential direction and gives rise to dissipation via the resistor when the particle moves and hence induces a current in the electrical circuit. Replacing the condenser plates by Helmholtz coils gives rise to “magnetic baths” interacting with, e.g., a paramagnetic particle [9]. Replacing the condenser plates by piezo elements gives rise to “acoustomechanical” baths [14]. (c) Only one heat bath (with temperature $T^{\prime }$) is of the anisotropic type as in (a) and (b). The second heat bath (with temperature $T$) consists of the usual fluid environment of the Brownian particle.Reuse & Permissions