Speaker
Ryoichi Kawai
(University of Alabama at Birmingham)
Description
Thermodynamics of nano-sized systems interacting with
environments must take into account quantum effects such as
system-environment entanglement and environment-induced
decoherence, in particular when the coupling with the
environments is strong. In a typical thermodynamics
scenario, a non-equilibrium system state relaxes to a unique
equilibrium state (Gibbs state) whose density matrix is
diagonal in the system energy eigenbasis, indicating that
coherence among the energy eigenstates is entirely lost. It
has been shown that such a kind of decoherence is limited to
the weak coupling. When the coupling is strong, the system
may reach a steady state where decoherence takes a place in
different basis sets. The steady state may not be unique.
The situation is even more complicated when the dynamics is
not Markovian. Decoherence has been intensively
investigated in other fields of physics, namely quantum
measurement theory and quantum computing. In the present
talk, I will attempt to relate some thermodynamic behaviors,
such as relaxation, heat conduction, and heat engine, to
such decoherence theory and demonstrate it using
non-Markovian open quantum mechanics approach. Some purely
quantum effects such as the disappearance of heat conduction
due to quantum Zeno effect will be discussed.
