Thermal Diode: Rectification of Heat Flux

By coupling two nonlinear one dimensional lattices, we demonstrate a thermal diode model that works in a wide range of system parameters. We provide numerical and analytical evidence for the underlying mechanism which allows heat flux in one direction while the system acts like an insulator when the temperature gradient is reversed. The possible experimental realization in nanoscale systems is briefly discussed.

Figure 1

Heat current $J$ versus the dimensionless temperature difference $\Delta$ for different values of $T_0$. Here the total number of particles $N=100$, $k_{\mathrm{i}\mathrm{n}\mathrm{t}}=0.05$, $\lambda =0.2$. The lines are drawn to guide the eye.

Figure 2

(a) Heat current $|J_{\pm }|$ versus the interface elastic constant $k_{\mathrm{i}\mathrm{n}\mathrm{t}}$ for $N=100$, $\lambda =0.2$, $T_{+}=0.105$, $T_{-}=0.035$. The solid circles are the current $J_{+}$ while empty circles are the current $J_{-}$. Inset in (a) is $|J_{\pm }|$ versus $k_{\mathrm{i}\mathrm{n}\mathrm{t}}$ for a system of eight particles. The solid lines in the figure and in the inset have slope equal two. (b) The temperature profile for $k_{\mathrm{i}\mathrm{n}\mathrm{t}}=0.01$, 0.05, 0.2 for the same parameters of (a).

Figure 3

Heat current versus $\lambda$ for $k_{\mathrm{i}\mathrm{n}\mathrm{t}}=0.2$ (circles), and $k_{\mathrm{i}\mathrm{n}\mathrm{t}}=0.05$ (triangles). The solid symbols refer to $T_{\mathrm{L}}=T_{+}$, $T_{\mathrm{R}}=T_{-}$, while empty symbols refer to $T_{\mathrm{L}}=T_{-}$, $T_{\mathrm{R}}=T_{+}$. Here $T_{+}=0.105$, $T_{-}=0.035$ and $N=100$.

Figure 4

Spectra of the two particles at the interface for different temperatures at $k_{\mathrm{i}\mathrm{n}\mathrm{t}}=0$. (a) Particle at the left side of the interface. (b) Particle at the right side of the interface. Here $\lambda =0.2$, $N=100$.

Figure 5

The finite size effect of the rectifying efficiency. Here we plot $|J_{+}|$ (solid circles) and $|J_{-}|$ (empty circles) versus $N$. Parameters are $\lambda =0.2$, $k_{\mathrm{i}\mathrm{n}\mathrm{t}}=0.05$, $T_{+}=0.105$, and $T_{-}=0.035$.