Kondo Dynamics in a Nanocontact System under Bias

Kondo dynamics in a nanocontact system under bias is one of unsettled problems in condensed matter physics because no successful skill handling the steady state of a strongly correlated system exists. In this colloquium, I introduce Kondo dynamics and many-body coherence in pedagogical manner and clarify the difference between conventional Kondo dynamics and new Kondo dynamics observed in a nanocontact system. I will show that the tunneling conductance observed in various nanocontact systems such as quantum point contact and scanning tunneling spectroscopy for samples with strong electron correlation can be understood by the resonant tunneling of a Fermi liquid quasiparticle through the Fermi level (zero-bias peak) and a coherent tunneling level (side peaks) that is formed in a two-reservoir quantum impurity system.