Motivated by the recent emergence of a new class of anisotropic 2D materials,
we examine their electromagnetic modes and demonstrate that a broad class of
the materials can host highly directional hyperbolic plasmons. Their
propagation direction can be manipulated on-the-spot by gate doping, enabling
hyperbolic beams reflection, refraction and bending. The realization of these
natural 2D hyperbolic media opens up a new avenue in dynamic control of
hyperbolic plasmons not possible in the 3D version.Comment: 5 pages, 4 figure