In this thesis, the effect of dissipation is investigated in driven models of interest for quantum annealing and quantum topological pumping. Dissipation comes from coupling the system to a bosonic bath at thermal equilibrium, using the usual Caldeira-Leggett setting. The first original results presented deal with the dissipative Landau-Zener model, where we revisit the issue of whether dissipation can improve the final ground state probability. We shed light upon the importance of the coupling direction. Then, we move to dissipation effects in the quantum annealing of the Ising chain in transverse field: we study the conditions for the emergence or absence of an optimal annealing velocity, depending on system-bath interaction strength and bath temperature. Finally, we explore dissipation effects in topological pumping in the periodically-driven Rice-Mele model, where we find that a bath at low temperature can improve the pumping performance when adiabaticity is not perfectly fulfilled.
|Titolo:||Dissipation effects in driven quantum many-body systems|
|Data di pubblicazione:||24-ott-2019|
|Appare nelle tipologie:||8.1 PhD thesis|