Low-speed Relativistic Phenomena

 If we have macroscopic quantum phenomena, why not low-speed relativistic phenomena?!

In fact, the first example already exists: Graphene! which has

$$E=pv_F,$$

where \(v_F\) is the Fermi velocity. This suggests that \(v_F\) plays the role of \(c\)

$$\gamma_F=\frac{1}{\sqrt{1-(\frac{v}{v_F})^2}}$$

Material with zero band-gap on an interval

 In graphene, bands meet at special points. Is it possible to create a material whose bands meet at special lines?

Electromagnetic Euler Force

 $$\textbf{F}=\textbf{r}\times\frac{\partial\textbf{B}}{\partial t}=-\textbf{r}\times(\nabla\times\textbf{E})$$