Title: Non-adiabatic work transfer

Bahar Mehmani - Sept 01 2008

Abstract

When a quantum system adiabatically evolves in a cyclic way, its wave function acquires a phase factor, the so called Berry phase. It is a geometric phase which can be measured via interference.
As a model we consider a quantum system coupled to two classical systems (work sources), where the couplings vary in a cyclic but non-adiabatic way. We investigate the corrections to the geometric phase due to the transitions to other energy levels.
It is shown that in the near adiabatic regime, i.e., first order correction, the total extracted work in a cycle from the system is zero but there is a non-zero work transfer due to the non-adiabatic corrections to the geometric phase. This can be explained as the work of the geometric force exerted from the system on the sources.
The second order non-adiabatic correction to the geometric phase makes it possible to extract work from the system in a cycle. The work transfer in this regime exhibits interesting features as well.