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Comment: Published in Phys. Rev. B
Comment: pdflatex, 3 pages, 3 figures
Comment: 12 pages, 10 figures
Comment: 6 pages, 4 figures
Comment: 10 pages, 9 figures, to appear in Phys. Rev. B
Comment: 4 pages, 3 figures, RevTeX
The Sagnac effect is an important phase coherent effect in optical and atom
interferometers where rotations of the interferometer with respect to an
inertial reference frame result in a shift in the interference pattern
proportional to the rotation rate. Here we analyze for the first time the
Sagnac effect in a mesoscopic semiconductor electron interferometer. We include
in our analysis Rashba spin-orbit interactions in the ring. Our results
indicate that spin-orbit interactions increase the rotation induced phase
shift. We discuss the potential experimental observability of the Sagnac phase
shift in such mesoscopic systems.
Comment: 7 pages, 7 figures
The ability to control the conductance of single molecules will have a major
impact in nanoscale electronics. Azobenzene, a molecule that changes
conformation as a result of a trans/cis transition when exposed to radiation,
could form the basis of a light-driven molecular switch. It is therefore
crucial to clarify the electrical transport characteristics of this molecule.
Here, we investigate theoretically charge transport in a system in which a
single azobenzene molecule is attached to two carbon nanotubes. In clear
contrast to gold electrodes, the nanotubes can act as true nanoscale electrodes
and we show that the low-energy conduction properties of the junction may be
dramatically modified by changing the topology of the contacts between the
nanotubes and the molecules, and/or the chirality of the nanotubes (that is,
zigzag or arm...
A real-space quantum transport simulator for carbon nanoribbon (CNR) MOSFETs
has been developed. Using this simulator, the performance of carbon nanoribbon
(CNR) MOSFETs is examined in the ballistic limit. The impact of quantum effects
on device performance of CNR MOSFETs is also studied. We found that 2D
semi-infinite graphene contacts provide metal-induced-gap-states (MIGS) in the
CNR channel. These states would provide quantum tunneling in the short channel
device and cause Fermi level pining. These effects cause device performance
degradation both on the ON-state and the OFF-state. Pure 1D devices (infinite
contacts), however, show no MIGS. Quantum tunneling effects are still playing
an important role in the device characteristics. Conduction due to band-to-band
tunneling is accurately captured in our simulations. It is important...