Monday 20 December; Delft; Klaus Ensslin "Coherent phonons in double dots"



Time:  11:00 hrs

Location: Room G (TNW building)

abstract: double quantum dots have been fabricated on graphene as well as on InAs nanowires. For finite bias we observe excited states whose energy scale ( ≈ meV) agrees with the size of the dot. In addition a series of almost equidistant levels (≈ 01.-0.2 meV) is detected. For InAs nanowire quantum dots the effect is so pronounced that the current through the dot is modulated on the 50-80% level. For graphene double dots similar features are detected in the differential conductance. We argue that the distance between the quantum dots selects a specific type of phonon and that an interference effect occurs involving both ground and excited electronic states as well as emitted phonons