Quench Dynamics in the Multi-Channel Kondo system

The Sachdev-Ye-Kitaev(SYK) model is an interesting model which shows the non-Fermi liquid state and the quantum chaotic behavior with the exact solvability in the large-N limit. Recently, there have been many studies done about the non-equilibrium properties of the SYK model regarding quantum chaos and thermalization in strongly interacting systems. However, the SYK model is more likely a toy model which is difficult to realize in real systems despite there having been some proposals. In this study, instead of the SYK model, we used the Multi-Channel Kondo model, which has many similarities to the SYK model but is more realizable in the real system, to investigate the non-equilibrium properties of the non-Fermi liquid state under sudden quench of the Kondo coupling constant. Using the Keldysh formalism, we obtained the Kadanoff-Baym equations and solved them numerically. Under several different conditions such as initial temperature, we have observed the thermalization process. To analyze the thermalization process quantitatively, we calculated the final temperature and thermalization time. We also obtained the change of the spin susceptibility under the sudden quench which can be measured in the experiment. In addition, we are calculating the Lyanupov exponent to see the effects of quantum chaos on thermalization.