Generating and detecting electron spin entangled states in nanostructures

We discuss various approaches to create and detect electron spin entanglement, with a special emphasis on the study of the efficiency of a beam splitter as a detector for entangled electron pairs. In particular, we focus on the consequence of considering wavepacket states for the electrons as they enter the beam splitter in order to illustrate their particle characteristics. We then introduce double quantum dot as a possible source of spin entangled electrons. In particular, we show that a double quantum dot turnstile is, in principle, an efficient electron spin entangler or entanglement filter because of the exchange coupling between the dots and the tunable input/output potential barriers.