Soutenance de thèse de Yukun GUO

Résumé : "In this thesis, I present new results regarding the measurement of the mobility edge in the Anderson transition, which was conducted in the Quantum Gas group. Measuring the mobility edge of the Anderson transition is very challenging. The broad energy dispersion in the disordered potential was the major bottleneck for experimental research with ultralcold atoms in the past decade. To overcome this limitation, the team has proposed a spectroscopy scheme in state-dependent disorder to perform an energy-resolved loading of atoms in disorder by rf-transfer. Our team realized the rf-transfer in 2018. However, at that time, the limited lifetime of atoms in the disorder-sensitive state prevented the observation of transport of atoms in disorder.

 

To address this issue, we present a new method of bichromatic state-dependent disorder, which has a low spontaneous scattering rate for the atoms in disorder. The setup allows for long observation periods in the order of seconds. During my PhD, we have checked this scheme experimentally. Based on this setup, we have tried to measure the mobility edge with the spectroscopic method. Though preliminary, our results show a fair agreement with the numerical prediction. These promising results pave the way for a detailed study of the critical regime."