80 research outputs found
Role of Phonon Scattering in Graphene Nanoribbon Transistors: Non-Equilibrium Green's Function Method with Real Space Approach
Mode space approach has been used so far in NEGF to treat phonon scattering
for computational efficiency. Here we perform a more rigorous quantum transport
simulation in real space to consider interband scatterings as well. We show a
seamless transition from ballistic to dissipative transport in graphene
nanoribbon transistors by varying channel length. We find acoustic phonon (AP)
scattering to be the dominant scattering mechanism within the relevant range of
voltage bias. Optical phonon scattering is significant only when a large gate
voltage is applied. In a longer channel device, the contribution of AP
scattering to the dc current becomes more significant
Proposal of a spin torque majority gate logic
A new spin based logic device is proposed. It is comprised of a common free
ferromagnetic layer separated by a tunnel junction from three inputs and one
output with separate fixed layers. It has the functionality of a majority gate
and is switched by spin transfer torque. Validity of its logic operation is
demonstrated by micromagnetic simulation. A version of such devices with
perpendicular magnetization is examined. Switching encompasses moving domain
walls. The device reuses most of the materials and structures from spin torque
RAM, and is entirely compatible with CMOS technology.Comment: 14 pages, 4 figure
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