Principal Investigator, projet Quantum Matter under Magnetic Field.
The IPCF Quantum Matter under magnetic field group is interested in electronic properties of dilute metals in the presence of a magnetic field. Under the effect of the magnetic field, the electrons move along helices with a radius rc (the cyclotron radius). As the magnetic field increases, rc decreases and becomes comparable to the different characteristic length scales of the material under study. At low magnetic field, rc is comparable with the electronic mean free path and the dynamic of the electron is well described by a semi-classical approach. At higher magnetic field, when rc is comparable to the Fermi wavelength (λF), it is expected that the quantum nature of the electron affects the electronic ground states. It is in this so-called "quantum limit" that the quantum Hall effect is observed in two-dimensional electron gases. Paradoxically, this limit has been poorly studied in three-dimensional electron gases, essentially for a practical reason: in the case of copper (or a standard metal), the magnetic field necessary to reach this limit is of the order of 5000T. On the other hand, in the case of diluted metals, this limit is much lower, of the order of several Teslas. We are thus studied the organization of electrons beyond the quantum limit in dilute metals using various type of transport measurements.
