title: Density functional theory based study of graphene and dielectric oxide interfaces.
abstract: We study the effects of insulating oxides in their crystalline forms on the energy band structure of monolayer and bilayer graphene using a first principles density functional theory based electronic structure method and a local density approximation. We consider the dielectric oxides SiO(2) (α-quartz) and Al(2)O(3) (alumina or α-sapphire), each with two surface terminations. Our study suggests that atomic relaxations and resulting equilibrium separations play a critical role in perturbing the linear band structure of graphene in contrast to the less critical role played by dangling bonds that result from cleaving the crystal in a particular direction. For Si-terminated quartz a Dirac cone is retained while it is restored on adding a second graphene layer for O-terminated quartz. Alumina needs more than two graphene layers to preserve the Dirac cone. Our results are, at best, semi-quantitative for the common amorphous forms of the oxides considered.
authors: Microelectronics Research Center, The University of Texas at Austin, Austin, TX 78758, USA. priyamvada@mail.utexas.edu
authors: Priyamvada
authors: P
authors: Jadaun
authors: Sanjay K
authors: SK
authors: Banerjee
authors: Leonard F
authors: LF
authors: Register
authors: Bhagawan
authors: B
authors: Sahu