▎ 摘　　要

The lattice Hamiltonian is diagonalized, including the next nearest hopping, Rashba spin-orbit coupling, and sublattice disorder terms, in order to exploit the low-energy electronic structure of a zigzag strip of graphene and present its behavior near the band-crossing points. The modes localized at strip edges reveal a peculiar electronic density of states near the Fermi level. In the absence of spin-orbit interactions, the edge states never cross the bulk band gap for finite values of the staggered sublattice potential, irrespective of its magnitude, and open an edge-state gap showing normal semiconductor behavior. We also discuss the temperature behavior of the electronic specific heat of the graphene strip.