Parameters of Magic-Angle Twisted Bilayer Graphene (MATBG) Superconductors

Abstract

In general, a superconducting state is described by three critical parameters, such as, critical transition temperature (Tc), critical magnetic field (Hc), and critical current density (Jc) or density of states at the Fermi surface of the superconductor. In the case of Magic-angle-twisted-bilayer-graphene (MATBG), the angle of twist ( )  kT = Constant between the two layers of graphene is another important parameter since the variation in  changes the value of Tc, and by virtue of the relation between Tc and EF (Fermi energy),  of states ( ) D E F E F the value of F E changes. Change in F E can result in the change in density , and thus it can affect the current density. Hence in MATBG, the magic angle( )  of twist between the graphene layers becomes an essential parameter along with the three parameters ( c T H c , and c J , ) that influence superconductivity in such materials, and the parameters are calculated for MATBG.