Effect of interlayer coupling on the electron spectra of vertical superlattice

By use of the Green's function method analytical expressions for the dispersion lows of superlattice (SL) consists of two alternating 2D layers are obtained. Weak interlayer coupling regime is analized thoroughly. As the examples, the SLs graphene – h-BN (1), AlN – GaN (2), Gr – Ni (3) and h-BN – Ni (4) are considered and analytical electron spectrum characteristics for the corresponding 2D layers are given. It is shown that 1) electron effective masses become havier for the h-BN, AlN, GaN, and Ni layers in all SLs; 2) Fermi velocity becomes lower for the gapless graphene layer in the SL (1) and remains constant in the SL (3); 3) energy gaps become narrower for the h-BN, AlN and GaN layers in the SLs (1) and (2) and wider for h-BN layer in the SL (4).