We investigate the atomic-scale tunneling characteristics of bilayer graphene on silicon carbide using the scanning tunneling microscopy. The high-resolution tunneling spectroscopy reveals an unexpected negative differential resistance (NDR) at the Dirac energy, which spatially varies within the single unit cell of bilayer graphene. The origin of NDR is explained by two near-gap van Hove singul...

Graphene is considered to be a promising candidate for future nanoelectronics due to its exceptional electronic properties. Unfortunately, the graphene field-effect transistors (FETs) cannot be turned off effectively due to the absence of a band gap, leading to an on/off current ratio typically around 5 in top-gated graphene FETs. On the other hand, theoretical investigations and optical measur...

The interaction of graphene with metal is of critical importance for further optimization of the growth and transfer processes to achieve productive graphene. Here we report first-principles calculations with van der Waals corrections to address in-plane orientation effects on the geometric structure and electronic properties of monolayer and bilayer graphene on a Ru(0001) surface. We find that...

Closed edges bilayer graphene (CEBG) is a recent discovered novel form of graphene structures, whose regulated edge states may critically change the overall electronic behaviors. If stacked properly with the AB style, the bilayer graphene with closed zigzag edges may even present amazing electronic properties of bandgap opening and charge separation. Experimentally, the CEBG has been confirmed ...

The growth of large-area bilayer graphene has been of technological importance for graphene electronics. The successful application of graphene bilayers critically relies on the precise control of the stacking orientation, which determines both electronic and vibrational properties of the bilayer system. Toward this goal, an effective characterization method is critically needed to allow resear...

Submitted for the MAR11 Meeting of The American Physical Society Boundary properties between monolayer and bilayer graphene and valley filter TAKESHI NAKANISHI, AIST, MIKITO KOSHINO, Tohoku Univ., TSUNEYA ANDO, Tokyo Inst. Tech. — Graphene consists of a twodimensional hexagonal crystal of carbon atoms, in which electron dynamics is governed by the Dirac equation. The purpose of this paper is to...

The intrinsic spin–orbit interactions in bilayer graphene and in graphite are studied, using a tight binding model and an intra-atomic E LE S coupling. The spin–orbit interactions in bilayer graphene and graphite are larger, by about one order of magnitude, than the interactions in single-layer graphene, due to the mixing of π and σ bands by interlayer hopping. Their values are in the range 0.1...

We consider bilayer graphene in the presence of spin orbit coupling, to assess its behavior as a topological insulator. The first Chern number n for the energy bands of single and bilayer graphene is computed and compared. It is shown that for a given valley and spin, n in a bilayer is doubled with respect to the monolayer. This implies that bilayer graphene will have twice as many edge states ...

We investigate band gap tuning of bilayer graphene between hexagonal boron nitride sheets, by external electric fields. Using density functional theory, we show that the gap is continuously tunable from 0 to 0.2 eV and is robust to stacking disorder. Moreover, boron nitride sheets do not alter the fundamental response from that of free-standing bilayer graphene, apart from additional screening....

Nanoelectromechanical systems constitute a class of devices lying at the interface between fundamental research and technological applications. Realizing nanoelectromechanical devices based on novel materials such as graphene allows studying their mechanical and electromechanical characteristics at the nanoscale and addressing fundamental questions such as electron-phonon interaction and bandga...