1,396 research outputs found
Shot Noise in Anyonic Mach-Zehnder Interferometer
We show how shot noise in an electronic Mach-Zehnder interferometer in the
fractional quantum Hall regime probes the charge and statistics of quantum Hall
quasiparticles. The dependence of the noise on the magnetic flux through the
interferometer allows for a simple way to distinguish Abelian from non-Abelian
quasiparticle statistics. In the Abelian case, the Fano factor (in units of the
electron charge) is always lower than unity. In the non-Abelian case, the
maximal Fano factor as a function of the magnetic flux exceeds one.Comment: references adde
Full counting statistics of Luttinger liquid conductor
Non-equilibrium bosonization technique is used to study current fluctuations
of interacting electrons in a single-channel quantum wire representing a
Luttinger liquid (LL) conductor. An exact expression for the full counting
statistics of the transmitted charge is derived. It is given by Fredholm
determinant of the counting operator with a time dependent scattering phase.
The result has a form of counting statistics of non-interacting particles with
fractional charges, induced by scattering off the boundaries between the LL
wire and the non-interacting leads.Comment: 5 pages, 2 figure
Universal Conductance Distribution in the Quantum Size Regime
We study the conductance (g) distribution function of an ensemble of isolated
conducting rings, with an Aharonov--Bohm flux. This is done in the discrete
spectrum limit, i.e., when the inelastic rate, frequency and temperature are
all smaller than the mean level spacing. Over a wide range of g the
distribution function exhibits universal behavior P(g)\sim g^{-(4+\beta)/3},
where \beta=1 (2) for systems with (without) a time reversal symmetry. The
nonuniversal large g tail of this distribution determines the values of high
moments.Comment: 13 pages+1 figure, RevTEX
An Analytical Approach to Neuronal Connectivity
This paper describes how realistic neuromorphic networks can have their
connectivity properties fully characterized in analytical fashion. By assuming
that all neurons have the same shape and are regularly distributed along the
two-dimensional orthogonal lattice with parameter , it is possible to
obtain the accurate number of connections and cycles of any length from the
autoconvolution function as well as from the respective spectral density
derived from the adjacency matrix. It is shown that neuronal shape plays an
important role in defining the spatial spread of network connections. In
addition, most such networks are characterized by the interesting phenomenon
where the connections are progressively shifted along the spatial domain where
the network is embedded. It is also shown that the number of cycles follows a
power law with their respective length. Morphological measurements for
characterization of the spatial distribution of connections, including the
adjacency matrix spectral density and the lacunarity of the connections, are
suggested. The potential of the proposed approach is illustrated with respect
to digital images of real neuronal cells.Comment: 4 pages, 6 figure
Incoherent scatterer in a Luttinger liquid: a new paradigmatic limit
We address the problem of a Luttinger liquid with a scatterer that allows for
both coherent and incoherent scattering channels. The asymptotic behavior at
zero temperature is governed by a new stable fixed point: a Goldstone mode
dominates the low energy dynamics, leading to a universal behavior. This limit
is marked by equal probabilities for forward and backward scattering.
Notwithstanding this non-trivial scattering pattern, we find that the shot
noise as well as zero cross-current correlations vanish. We thus present a
paradigmatic picture of an impurity in the Luttinger model, alternative to the
Kane-Fisher picture.Comment: published version, 4 + epsilon pages, 1 figur
Conductance of Aharonov--Bohm Rings: From the Discrete to the Continuous Spectrum Limit
The dissipative conductance of an array of mesoscopic rings, subject to an
a.c. magnetic flux is investigated. The magneto--conductance may change sign
between canonical and grand-canonical statistical ensembles, as function of the
inelastic level broadening and as function of the temperature. Differences
between canonical and grand-canonical ensembles persist up to temperature of
the order of the Thouless energy.Comment: 13 pages, 2 figures, REVTeX v2.1, WIS--93/121/Dec.--P
Critical behavior of the 3-state Potts model on Sierpinski carpet
We study the critical behavior of the 3-state Potts model, where the spins
are located at the centers of the occupied squares of the deterministic
Sierpinski carpet. A finite-size scaling analysis is performed from Monte Carlo
simulations, for a Hausdorff dimension . The phase
transition is shown to be a second order one. The maxima of the susceptibility
of the order parameter follow a power law in a very reliable way, which enables
us to calculate the ratio of the exponents . We find that the
scaling corrections affect the behavior of most of the thermodynamical
quantities. However, the sequence of intersection points extracted from the
Binder's cumulant provides bounds for the critical temperature. We are able to
give the bounds for the exponent as well as for the ratio of the
exponents , which are compatible with the results calculated from
the hyperscaling relation.Comment: 13 pages, 4 figure
Zero bias anomaly out of equilibrium
The non-equilibrium zero bias anomaly (ZBA) in the tunneling density of
states of a diffusive metallic film is studied. An effective action describing
virtual fluctuations out-of-equilibrium is derived. The singular behavior of
the equilibrium ZBA is smoothed out by real processes of inelastic scattering.Comment: 4 page
What is the Thouless Energy for Ballistic Systems?
The Thouless energy, \Ec characterizes numerous quantities associated with
sensitivity to boundary conditions in diffusive mesoscopic conductors. What
happens to these quantities if the disorder strength is decreased and a
transition to the ballistic regime takes place? In the present analysis we
refute the intuitively plausible assumption that \Ec loses its meaning as an
inverse diffusion time through the system at hand, and generally disorder
independent scales take over. Instead we find that a variety of (thermodynamic)
observables are still characterized by the Thouless energy.Comment: 4 pages REVTEX, uuencoded file. To appear in Physical Review Letter
Cold bosons in the Landauer setup
We consider one dimensional potential trap that connects two reservoirs
containing cold Bose atoms. The thermal current and single-particle bosonic
Green functions are calculated under non-equilibrium conditions. The bosonic
statistics leads to Luttinger liquid state with non-linear spectrum of
collective modes. This results in suppression of thermal current at low
temperatures and affects the single-particle Green functions.Comment: 10 pages, 6 figure
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