7 research outputs found
Aharonov-Bohm effect in circular carbon nanotubes
We study the interference of interacting electrons in toroidal single-wall
carbon nanotubes coupled to metallic electrodes by tunnel junctions. The dc
conductance shows resonant features as a function of the gate voltage and the
magnetic field. The conductance pattern is determined by the interaction
parameter, which in turn can be cross-checked against the exponents governing
the transport at high temperatures. The coordinate dependence of the
conductance reflects electron correlations in one-dimensional space.Comment: 2 pages, contributed paper to LT-22, style file phbauth.cls is
include
Towards single-electron metrology
We review the status of the understanding of single-electron transport (SET)
devices with respect to their applicability in metrology. Their envisioned role
as the basis of a high-precision electrical standard is outlined and is
discussed in the context of other standards. The operation principles of single
electron transistors, turnstiles and pumps are explained and the fundamental
limits of these devices are discussed in detail. We describe the various
physical mechanisms that influence the device uncertainty and review the
analytical and numerical methods needed to calculate the intrinsic uncertainty
and to optimise the fabrication and operation parameters. Recent experimental
results are evaluated and compared with theoretical predictions. Although there
are discrepancies between theory and experiments, the intrinsic uncertainty is
already small enough to start preparing for the first SET-based metrological
applications.Comment: 39 pages, 14 figures. Review paper to be published in International
Journal of Modern Physics
Electronic Properties of Armchair Carbon Nanotubes : Bosonization Approach
The phase Hamiltonian of armchair carbon nanotubes at half-filling and away
from it is derived from the microscopic lattice model by taking the long range
Coulomb interaction into account. We investigate the low energy properties of
the system using the renormalization group method. At half-filling, the ground
state is a Mott insulator with spin gap, in which the bound states of electrons
at different atomic sublattices are formed. The difference from the recent
results [Phys. Rev. Lett. 79, 5082 (1997)] away half-filling is clarified.Comment: 4 pages, 1 figure, Revte
Universality of electron correlations in conducting carbon nanotubes
Effective low-energy Hamiltonian of interacting electrons in conducting
single-wall carbon nanotubes with arbitrary chirality is derived from the
microscopic lattice model. The parameters of the Hamiltonian show very weak
dependence on the chiral angle, which makes the low energy properties of
conducting chiral nanotubes universal. The strongest Mott-like electron
instability at half filling is investigated within the self-consistent harmonic
approximation. The energy gaps occur in all modes of elementary excitations and
estimate at eV.Comment: 4 pages, 2 figure