MeQuaNo project : from few electron statistics to shot noise
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(top) principle of the n-electron coherent source
(bottom) schematic view of a Photo-Assisted Shot Noise (PASN) detector

We propose innovative approaches to electronic quantum noise going from very fundamental topics addressing the quantum statistics of few electrons transferred through conductors to direct applications with the realization of new types of versatile broadband photon detectors based on photon-assisted shot noise.

  • Quantum statistics of few electrons

A fundamental issue not experimentally solved yet is the possibility to access full counting statistics of electrons crossing a conductor. While some experiments trys to adress the problem by measuring current fluctuations and its higher moments, we propose another approach directly connected to electron statistics. This new approach consist in injecting small controlled number of electrons in a conductor followed by detection of the exact number of electrons arrived in the contacts. Electrons are injected in a form of a coherent collective wavepacket ( a 'Slater determinant' immediately above the Fermi sea) following the proposal of L. Levitov et al. of a n-electron coherent source. Generation of few electron bunches will be obtained by the yet never done technique of short voltage pulses whose duration is limited to few action quanta, one quantum for one electron. Detection of electron bunches will be done by an unprecedented ‘cut 'n probe’ technique where carriers are suddenly isolated in the circuit for further sensitive charge detection

This approach should allow not only for a full characterization of the electron statistics but also will open the way to new quantum interference experiments involving few electrons or fractional charge carriers and will question our understanding of quantum statistics.

  • Application of shot noise : Photon assisted shot noise (PASN).

Using highly ballistic electron nanostructures such as Graphene, III-V semiconductors with light carriers, Carbone Nanotubes or simply tunnel barriers, we will bring mesoscopic quantum noise effects to higher temperature, energy and frequency range, and thus closer to applications. Inspired by late R. Landauer’s saying: “the noise IS the signal” we will develop totally new detectors based on the universal effect of photon-assisted electron shot noise. These versatile broadband detectors will be used either for on-chip noise detection or for photon radiation detection, possibly including imaging. They will operate above liquid Helium temperature and at THz frequencies although projected operation includes room temperature and far-infrared range as no fundamental limitation is expected.