Manipulation de gaz quantiques par des potentiels d’états doublement habillés : au-delà de la dynamique hermitienne
Ruiyang Huang
Ultracold atomic gas is a quantum system well-isolated from the environment, whose interaction with light is well understood. The ultracold gas thus becomes a highly performant quantum simulator to place under tailored potential generated by light. Observation of atom dynamics give answers to many quantum phenomena, such as the fractional quantum Hall effect, topological insulators, and superconductivity. In this context, diffraction-limited quantum gas microscopes have emerged as standard tools to probe such complex systems and to measure atomic density correlations between lattice sites. In addition, capability of manipulating the quantum gas microscopically opens the access to non-equilibrium many-body physics. In this PhD thesis, we investigate sub-wavelength control upon ultracold atoms using a dressed excited state method. We first characterized the excited state spectrum. From Lindblad master equations, a new form of ground state potential has been proposed to explain the coherent dynamics of the atomic wavefunction. We experimentally confirmed the correctness of the proposal through Kapitza-Dirac scattering. We then performed sub-wavelength microscopy on the smallest quantum object we could realize: the atomic wavefunction compressed in a tight optical lattice. Based on this microscopy technique, we could spatially resolve the coherent tunneling dynamics between lattice sites. By introducing site-resolved decay channel, quantum Zeno effect has been observed during the tunneling, opening the way to coherent control of an atomic wavefunction at sub-wavelength scales.
•Mar 16, 2026•0 citations