ﻻ يوجد ملخص باللغة العربية
The complex mechanisms governing charge migration in DNA oligomers reflect the rich structural and electronic properties of the molecule of life. Controlling the mechanical stability of DNA nanowires in charge transport experiments is a requisite for identifying intrinsic issues responsible for long range charge transfers. By merging density-functional-theory-based calculations and model-Hamiltonian approaches, we have studied DNA quantum transport during the stretching-twisting process of poly(GC) DNA oligomers. During the stretching process, local maxima in the charge transfer integral t between two nearest-neighbor GC pairs arise from the competition between stretching and twisting. This is reflected in local maxima for the conductance, which depend very sensitively on the coupling to the electrodes. In the case of DNA-electrode couplings smaller than t, the conductance versus stretching distance saturates to plateau in agreement with recent experimental observations.
Using a scanning tunnel microscope or mechanically controlled break junctions, atomic contacts of Au, Pt and Ir are pulled to form chains of atoms. We have recorded traces of conductance during the pulling process and averaged these for a large amoun
We study the conductance of a quantum wire in the presence of weak electron-electron scattering. In a sufficiently long wire the scattering leads to full equilibration of the electron distribution function in the frame moving with the electric curren
Precession and relaxation predominantly characterize the real-time dynamics of a spin driven by a magnetic field and coupled to a large Fermi sea of conduction electrons. We demonstrate an anomalous precession with frequency higher than the Larmor fr
We study the conductance threshold of clean nearly straight quantum wires in the magnetic field. As a quantitative example we solve exactly the scattering problem for two-electrons in a wire with planar geometry and a weak bulge. From the scattering
The contact conductance between graphene and two quantum wires which serve as the leads to connect graphene and electron reservoirs is theoretically studied. Our investigation indicates that the contact conductance depends sensitively on the graphene