Theoretical Physics Seminar: Andrew Ho (Royal Holloway)

Date: 26/10/2017

Time: 12:00-13:00

Location: EC Stoner 8.62

Reaching Thermal States in Quantum Systems

We study the decoherence and thermalization dynamics of a nanoscale
system coupled nonperturbatively to a fully quantum-mechanical
bath. The system is prepared out of equilibrium in a pure state of
the complete system with no system-bath coupling. This coupling is then
switched on suddenly and we track its  fully quantum time evolution. We
study both numerically and propose a random matrix model to show
analytically that there are two robust temporal regimes in the
approach of the system to equilibrium --- an initial Gaussian decay
followed by an exponential tail, consistent with our numerical results
on small interacting lattices . Furthermore, the system decays towards a
thermal ensemble in accordance with the Eigenstate Thermalization
Hypothesis.