Le mardi 8 décembre à 14H en vidéoconférence : https://cyu-fr.zoom.us/j/91385358459?pwd=Y1o0ZGFHRUROQXZaNFVyc2JsVkw3QT09#success (Meeting ID: 913 8535 8459 ; Passcode: 1h@awKJ)

Multifractality of wave packets at the metal/insulator Anderson transition

In dimension three, a disordered quantum system may have a transition between a metallic/diffusive phase at low disorder and a isolating/localized phase at strong disorder. In the vicinity of this so-called Anderson transition, it is well known that the wavefunctions of eigenstates display giant fluctuations and a multifractal character. In this thesis, we use a specific system, the quasi-periodically kicked rotor, in order to study the multifractal properties of wavepackets. This is a one-dimensional system which can be studied experimentally and for which numerical simulations are easy. The time-dependent character of the Hamiltonian is such that it displays a controlable Anderson transition. We study numerically and interpret theoretically the multifractal properties of wavepackets in the vicinity of the Anderson transition. We show that they make it possible to access the multifractality properties of eigenstates in dimension three, opening the way to a future experiment.