M2 Internship and PhD project: Quantum Signal Processing
PhD advisor: Pascal Degiovanni (DR2 CNRS).
Email: Pascal.Degiovanni@ens-lyon.fr
Address : Laboratoire de Physique de l'ENS de Lyon (UMR 5672), Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69007 Lyon, France.
Scientific context and motivation:
Over the last few years, groundbreaking experiments have enabled us to prepare, manipulate and characterize electrical currents propagating within ballistic quantum conductors, thereby realizing the electronic analogue of quantum optics. Such quantum currents can be viewed as quantum signals carried by a degenerate electron beam which can then be used to carry classical or quantum information.
Contrarily to a classical current, a quantum electrical current carries a much richer information than the particle flux as a function of time. The electronic fluid contains quantum as well as classical correlation whose origin can be traced back to fermionic statistics, thermal effect and most importantly electron/electron interactions. Understanding quantum signals is an important problem in the perspective of metrological applications of quantum electrical currents based on single to few excitations as well as for clarifying the potential of these currents for quantum information processing applications in low decoherence materials. On a more basic level, quantum signal processing aims at providing an operational framework for understanding and describing entanglement in a beam of quantum particles.
The research project:
This PhD project will focus on the measurement, characterization and representation of the « quantum signals » carried by a quantum electrical current. This groundbreaking perspective on quantum electronic transport is at the interface between quantum optics, mesoscopic physics, signal processing and quantum information. It will elaborate on the pioneering work of B. Roussel at ENS Lyon on electronic atoms of signal and will extend it to the description of second order electronic coherence, trying to find simple parametrizations of the quantum many body state of the electronic fluid beyond Wick's theorem from these quantum signal representations.
The project will involve a close collaboration with the G. Fève group which performs electron quantum optics experiments at the Laboratoire Pierre Aigrain (ENS Paris) and with Dr. B. Roussel from the Advanced Concept Team at the European Space Agency (Nordwiijk, Netherlands) whose PhD work has opened this new approach. On the signal processing side, we will collaborate with Prof. P. Flandrin (ENS Lyon) as well as with Dr. R. Bardenet (Lille University). The project will also be integrated in the SEQUOIA European project on electron quantum optics.
References: For a general introduction to electron quantum optics and quantum signal processing, please consult B. Roussel
et al,
Physica Status Solidi B 254, 1600621 (2017) and the companion review paper on Two-particle interferometry in quantum Hall edge channels by A. Marguerite
et al,
Physica Status Solidi B254, 20160618 (2017).
Practical information: I have the funding for an M2 Internship but funding is to be asked for the full PhD.