One could vary the device width, which will still result in qualitatively similar characteristics, as far as the conduction and valence band edges are well isolated from the near-midgap state. Next, we consider the transport through the graphene nanoribbon by applying drain bias. In the limit of small drain bias, the channel transport is only dependent on the MDV3100 bandwidth of the near-midgap state. For zero bandwidth, no channel current flows through this state in the coherent Angiogenesis inhibitor limit, except for the dielectric leakage current and tunneling

through the higher bands, which should be small given the conduction (valence) band is above (below) the localized state by about 1 eV. By applying a gate voltage to increase the bandwidth of the state, the channel current starts to flow. The operation of the EMT in this mode is equivalent to that of an n-MOS; hence, we refer to it as n-EMT. The equivalents of p-EMT can be realized by simply reversing the gate connections to induce an electric field in the reverse direction [8]. This all-electronic

scheme thus operates under complementary mode. We envision that such transistor action is more general and can be achieved in any dimension with a near-midgap state in the channel region, the bandwidth of which can be modulated by the external voltage and for which, one can make ohmic contacts with the midgap state. In the limit of high bias, this transport picture changes, which we discuss Org 27569 later. So far, to the best of our knowledge, an experimental observation of such a state in a zzGNR selleck screening library has not been made. Theoretical model To understand the transport in the high-bias regime, we consider a gedanken

one-dimensional device and start with the ansatz of Equation 1. For such a device, we use single-band tight-binding approximation [13], where the channel bandwidth is 4|t o| and t o is the nearest neighbor hopping parameter. For simplicity, we take five lattice points in the device region corresponding to a channel length and width of about 2 and 1 nm, respectively. The channel length can be decreased to about 1 nm as long as there is an unperturbed region in the middle with a near-midgap state, whereas the upper limit on the channel length can be bound by the scattering length, which can be in micrometer range for graphene. Similarly, the width can be varied as well which will result in a different gate voltage applied to achieve similar device characteristics. The Laplace’s potential due to the drain bias (V d) is included as a linear voltage drop. The Hartree potential is ignored for simplicity, since it does not affect the device operating principle, although it may affect the quantitative results. The choice of a simple model allows us to study the device and the circuit characteristics in terms of the modulation factor α and the residual bandwidth BWo.