Suppression and Control of Prethermalization in Multicomponent Fermi gases Following a Quantum Quench*

We investigate the mechanisms of control and suppression of prethermalization focusing on N-component alkaline-earth-like gases. Using time-dependent perturbatition theory, we compute the short-time dynamics of the instantaneous momentum distribution and the relative population for different initial conditions after an interaction quench, accounting for the effect of initial interactions. We find that switching on an interaction that breaks the SU(N) symmetry of the initial Hamiltonian, thus allowing for the occurrence of spin-changing collisions, does not necessarily lead to a suppression of prethermalization. However, the suppression will be most effective in the presence of SU(N)-breaking interactions provided the number of components N≥4 and the initial state contains a population imbalance that breaks the SU(N) symmetry. We also find the conditions on the imbalance initial state that allow for a prethermal state to be stabilized for a certain time. Our study highlights the important role played by the initial state in the prethermalization dynamics of multicomponent Fermi gases. It also demonstrates that alkaline-earth-metal Fermi gases provide an interesting playground for the study and control of prethermalization.