Proposal of a Realistic Stochastic Rotor Engine Based on Electron Shuttling

We propose and analyze an autonomous engine that combines ideas from electronic transport and self-oscillating heat engines. It is based on the electron-shuttling mechanism in conjunction with a rotational degree of freedom. We focus in particular on the isothermal regime, where chemical work is converted into mechanical work or vice versa, and we especially pay attention to using parameters estimated from experimental data of available single components. Our analysis shows that, for these parameters, the engine already works with remarkable stability, albeit with moderate efficiency. Moreover, it has the advantage that it can be upscaled to increase power and reduce fluctuations further.

Figure 1

(a) Proposed realization with a gold particle mounted onto a carbon nanotube (see main text). (b) Physically relevant quantities of the engine (details in the main text).

Figure 2

Probability density of the rotor $p(\varphi ,\omega )=\sum _{q}p(\varphi ,\omega ,q)$ in phase space (periodic in $\varphi$) for $\beta Mgr=2.0$ and different values of $\beta eV$.

Figure 3

Power output for different values of $\beta eV$ and $\beta Mgr$. Within the region enclosed by the red (blue) dashed line $⟨{\dot{W}}^m⟩>0\left(⟨{\dot{W}}^c⟩>0\right)$. The illustrations indicate the directionality of the weight (black) and the matter current (green). The green dashed line separates the two regimes by thermodynamic arguments (see main text) and the black lines correspond to the maximum power output curves. Inset: Efficiency at maximum power (red/blue for lifting/pumping).

Figure 4

Normalized fluctuations ${\sigma }^m$ (a) and ${\sigma }^c$ (b) as a function of $\beta eV$ for different values of $\beta Mgr$.

Figure 5

Work output $⟨{\dot{W}}^m⟩$ as function of $\beta eV$ for $\beta Mgr=0.6$ for different engine setups (see main text). Inset: Normalized fluctuations ${\sigma }^m$.