Gerbold Ménard

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The quantum coherence of single electronic states in mesoscopic system is usually very fragile. This fragility can be harnessed to create hyper-sensitive quantum sensors such that a single electron can detect a few photons excitation. In this work, we demonstrate a quantum sensor that exploits the variations of the phase of a single electron wavefunction upon its interaction with a classical time-dependent electric field. We use a Fabry-Perot interferometer in the quantum Hall regime to extract the phase of the wave packet as a function of time. Such device ensures a fast and sensitive detection as are able to detect a signal equivalent to a few microwave photons with a resolution of 50 ps. Moreover, by measuring both the phase and contrast of the interferometer, it is possible to obtain information on both the amplitude of the electromagnetic field and its fluctuations. This opens possibilities for on-chip detection of non-classical radiation such as squeezed states or Fock states.

[1] Bartolomei, Hugo, et al. "Time-resolved sensing of electromagnetic fields with single-electron interferometry." Nature Nanotechnologies https://rdcu.be/edRw8 (2025)

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CNRS - ENS Paris
Seminarraum I Physik
Contact: Erwann Bocquillon / Matteo Cacco