Effect of indirect interband transitions on terahertz conductivity in “decorated” graphene bilayer heterostructures

Abstract

We demonstrate that the indirect interband generation of photons in the optically or injection pumped graphene bilayer (GBL) heterostructures with an array of metal particles (GBLs “decorated” by metal particles) with population inversion can surpass their intraband (Drude) absorption. This can result in rather large absolute values of the negative dynamic terahertz (THz) conductivity in a wide range of frequencies at room temperature. This effect enables the creation of novel THz lasers based on the decorated GBLs.