Talk Title: Quantum criticality out of equilibrium in Kondo quantum dots Quantum phase transition out of equilibrium has attracted
much attention in strongly correlated electron systems at a nano-scale. A fundamentally
important issue is to ask whether universal scaling behaviors found in
equilibrium quantum phase transitions would be the same as those out of
equilibrium. In this talk, I review some of the recent progress on this topic.
Special focus will be on two generic models of quantum dots in the Kondo regime
subject to a finite bias voltage: (i) the two-channel Kondo model in quantum
dot, and (ii) the pseudogap Kondo quantum dot. Due to current-induced
decoherence, these systems show distinct nonequilibrium transport near phase
transitions from their equilibrium counterparts. I will demonstrate the
different roles played by the bias voltage in nonequilibrium systems from that
played by finite temperatures in equilibrium systems. New universal scaling
behaviors associated with these nonequilibrium quantum phase transitions are
discussed. |