Analysis of shot noise suppression in mesoscopic cavities in a magnetic field

We present a numerical investigation of shot noise suppression in mesoscopic cavities and an intuitive semiclassical explanation of the behavior observed in the presence of an orthogonal magnetic field. In particular, we conclude that the decrease of shot noise for increasing magnetic field is the result of the interplay between the diameter of classical cyclotron orbits and the width of the apertures defining the cavity. Good agreement with published experimental results is obtained, without the need of introducing fitting parameters.Comment: 5 pages, 3 figures, contents changed (final version

Positive Cross Correlations in a Normal-Conducting Fermionic Beam Splitter

We investigate a beam splitter experiment implemented in a normal conducting fermionic electron gas in the quantum Hall regime. The cross-correlations between the current fluctuations in the two exit leads of the three terminal device are found to be negative, zero or even positive depending on the scattering mechanism within the device. Reversal of the cross-correlations sign occurs due to interaction between different edge-states and does not reflect the statistics of the fermionic particles which `antibunch'.Comment: 4 pages, 4 figure

Dynamic generation of orbital quasiparticle entanglement in mesoscopic conductors

We propose a scheme for dynamically creating orbitally entangled electron-hole pairs through a time-dependent variation of the electrical potential in a mesoscopic conductor. The time-dependent potential generates a superposition of electron-hole pairs in two different orbital regions of the conductor, a Mach-Zehnder interferometer in the quantum Hall regime. The orbital entanglement is detected via violation of a Bell inequality, formulated in terms of zero-frequency current noise. Adiabatic cycling of the potential, both in the weak and strong amplitude limit, is considered.Comment: 4 pages, 2 figures; references update

Ehrenfest-time dependence of weak localization in open quantum dots

Semiclassical theory predicts that the weak localization correction to the conductance of a ballistic chaotic cavity is suppressed if the Ehrenfest time exceeds the dwell time in the cavity [I. L. Aleiner and A. I. Larkin, Phys. Rev. B {\bf 54}, 14424 (1996)]. We report numerical simulations of weak localization in the open quantum kicked rotator that confirm this prediction. Our results disagree with the `effective random matrix theory' of transport through ballistic chaotic cavities.Comment: 4 pages, 2 figure

The effect of symmetry class transitions on the shot noise in chaotic quantum dots

Using the random matrix theory (RMT) approach, we calculated the weak localization correction to the shot noise power in a chaotic cavity as a function of magnetic field and spin-orbit coupling. We found a remarkably simple relation between the weak localization correction to the conductance and to the shot noise power, that depends only on the channel number asymmetry of the cavity. In the special case of an orthogonal-unitary crossover, our result coincides with the prediction of Braun et. al [J. Phys. A: Math. Gen. {\bf 39}, L159-L165 (2006)], illustrating the equivalence of the semiclassical method to RMT.Comment: 4 pages, 1 figur

Full counting statistics of chaotic cavities with many open channels

Explicit formulas are obtained for all moments and for all cumulants of the electric current through a quantum chaotic cavity attached to two ideal leads, thus providing the full counting statistics for this type of system. The approach is based on random matrix theory, and is valid in the limit when both leads have many open channels. For an arbitrary number of open channels we present the third cumulant and an example of non-linear statistics.Comment: 4 pages, no figures; v2-added references; typos correcte

Quantum state tomography with quantum shotnoise

We propose a scheme for a complete reconstruction of one- and two-particle orbital quantum states in mesoscopic conductors. The conductor in the transport state continuously emits orbital quantum states. The orbital states are manipulated by electronic beamsplitters and detected by measurements of average currents and zero frequency current shotnoise correlators. We show how, by a suitable complete set of measurements, the elements of the density matrices of the one- and two-particle states can be directly expressed in terms of the currents and current correlators.Comment: 4 pages, 2 figure