193 research outputs found
Nonlinear conductance of nanowires - A signature of Luttinger liquid effects?
We analyze recent measurements of the room temperature current-voltage
characteristics of gold nanowires, whose zero current conductance is quantized
in units of . A faster than linear increase of current with voltage was
observed at low voltages beginning from V. We analyze the nonlinear
behavior in terms of a dynamic Coulomb blockade of conducting modes and show
that it may be explained as a Luttinger-liquid effect.Comment: 13 pages, latex with supplied stylefile, 3 figures in eps format,
submitted to Superlattices and Microstructure
Influence of the Rashba effect on the Josephson current through a superconductor/Luttinger liquid/superconductor tunnel junction
The Josephson current through a 1D quantum wire with Rashba spin-orbit and
electron-electron interactions is calculated. We show that the interplay of
Rashba and Zeeman interactions gives rise to a supercurrent through the 1D
conductor that is anomalous in the sense that it persists in the absence of any
phase difference between the two superconducting leads to which it is attached.
The electron dispersion asymmetry induced by the Rashba interaction in a
Luttinger-liquid wire plays a significant role for poorly transmitting
junctions. It is shown that for a weak or moderate electron-electron
interaction the spectrum of plasmonic modes confined to the normal part of the
junction becomes quasi-random in the presence of dispersion asymmetry.Comment: 25 pages, 3 figure
Coulomb Promotion of Spin-Dependent Tunnelling
We study transport of spin-polarized electrons through a magnetic
single-electron transistor (SET) in the presence of an external magnetic field.
Assuming the SET to have a nanometer size central island with a single electron
level we find that the interplay on the island between coherent spin-flip
dynamics and Coulomb interactions can make the Coulomb correlations promote
rather than suppress the current through the device. We find the criteria for
this new phenomenon -- Coulomb promotion of spin-dependent tunnelling -- to
occur.Comment: 4 pages, 3 figures; The new version has a slightly modified title, 2
more figures, and an extended analysis of the (same) results obtaine
Nanoelectromechanics of shuttle devices
A single-electron tunneling (SET) device with a nanoscale central island that
can move with respect to the bulk source- and drain electrodes allows for a
nanoelectromechanical (NEM) coupling between the electrical current through the
device and mechanical vibrations of the island. Although an electromechanical
"shuttle" instability and the associated phenomenon of single-electron
shuttling were predicted more than 15 years ago, both theoretical and
experimental studies of NEM-SET structures are still carried out. New
functionalities based on quantum coherence, Coulomb correlations and coherent
electron-spin dynamics are of particular current interest. In this article we
present a short review of recent activities in this area.Comment: 23 pages, 26 figure
Nanomechanics of a magnetic shuttle device
We show that self sustained mechanical vibrations in a model magnetic shuttle device can be driven by both the charge and the spin accumulated on the movable central island of the device. Different scenarios for how spin- and charge-induced shuttle instabilities may develop are discussed and shown to depend on whether there is a Coulomb blockade of tunneling or not. The crucial role of electronic spin flips in a magnetically driven shuttle is established and shown to cause giant magnetoresistance and dynamic magnetostriction effects
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