2,853 research outputs found
The Effect of Interaction on Shot Noise in The Quantum Limit
We employ a non-linear sigma model defined on a Keldysh contour to study the
current and the current noise in a diffusive micro-bridge in the presence of
electron-electron interactions. Out of equilibrium the fluctuation-dissipation
theorem (FDT) does not apply, hence these two quantities are not simply
interrelated. For a two-dimensional electron gas (2DEG) we obtain logarithmic
singularities in the low frequency limit. PACS Nos. 71.10.Ay, 71.23.An,
73.50.TdComment: Submitted to the proceedings of 36 Renconters de Moriond "Electronic
correlations: from meso- to nano-physics". One figure adde
Korshunov instantons out of equilibrium
Zero-dimensional dissipative action possesses non-trivial minima known as
Korshunov instantons. They have been known so far only for imaginary time
representation that is limited to equilibrium systems. In this work we
reconstruct and generalise Korshunov instantons using real-time Keldysh
approach. This allows us to formulate the dissipative action theory for generic
non-equilibrium conditions. Possible applications of the theory to transport in
strongly biased quantum dots are discussed..Comment: 6 pages, 2 figure
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
Cyclostationary measurement of low-frequency odd moments of current fluctuations
Measurement of odd moments of current fluctuations is difficult due to strict
requirements for band-pass filtering. We propose how these requirements can be
overcome using cyclostationary driving of the measured signal and indicate how
the measurement accuracy can be tested through the phase dependence of the
moments of the fluctuations. We consider two schemes, the mixing scheme and the
statistics scheme, where the current statistics can be accessed. We also
address the limitations of the schemes, due to excess noise and due to the
effects of the environment, and, finally, discuss the required measurement
times for typical setups.Comment: 13 pages, 3 figure
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