Figure 1

(Color online) Three-state model for a trivial Brownian vortex.Reuse & Permissions

Figure 2

(Color online) Forces in the three-state advection-diffusion model. Node 0 is designated as a trap.Reuse & Permissions

Figure 3

(Color online) (a) The states and transition rates for the general four-state Brownian vortex model. In addition to allowing transitions among neighboring states, this model also allows for unbiased transitions between nodes 1 and 3. (b) Sign convention for the local currents in the four-state model.Reuse & Permissions

Figure 4

(Color online) Forces in a minimal four-state model that supports temperature-dependent flux reversal.Reuse & Permissions

Figure 5

(Color online) Diagram showing the conditions of current reversal in the four-node model, in terms of rate constants $a$ and $d$ (upper figure) or in terms of corresponding energies $\alpha$ and $\delta$ (lower figure). All three currents vanish simultaneously for $a=d=1$, where detailed balance is obeyed or where the solenoidal force is absent. The upper diagram is superimposed with the contour plot of entropy production [Eq. (17)]: entropy production vanishes in the same equilibrium point $a=d=1$ and monotonously grows to positive values around this point. There is no direct obvious relation between the features of entropy production plot and the current reversal lines. For each region of the lower diagram, the small schemes show the directions of all three currents in the system: $J$, $J_0$, and $J_1$. The constant temperature experiment corresponds to sliding along a straight line passing through the origin in the lower figure, with the direction of the line being determined by the ratio of energies $\alpha$ and $\delta$.Reuse & Permissions