Entanglement production in a quantum heat engine

Abstract: Entanglement production is one of the properties of interest when studying nanoscale systems. Not only does entanglement between subsystems hints at other non-classical behaviour and effects that may be of interest to applications; the resource of entangled systems themselves is one on which many future devices and protocols may depend on. In this thesis work, a system of two quantum dots coupled in series between two fermionic leads is considered. The system is a fermionic version of the qubit system studied previously by J. B. Brask et. al. Assuming steady state, the density matrix of the double dot subsystem is calculated by first finding the retarded Green's functions of the system, and then showing the connection between these Green's functions and the elements of the density matrix. From the density matrix, the entanglement produced between the two quantum dots is extracted. This result is compared to and shown to agree with previous theoretical results, where instead a Markovian master equation approach was used to find the density matrix. Finally, in the discussion and outlook sections possible next steps in the calculation are discussed, as well as the advantages of the Green's functions method over the Markovian master equation approach.