title: Infrared transmission spectroscopy of  charge carriers in self-assembled InAs  quantum dots under surface electric fields.
abstract: We present a study on the intersublevel spacings of electrons and holes in a single layer of InAs self-assembled quantum dots. We use Fourier transform infrared transmission spectroscopy via a density chopping scheme for direct experimental observation of the intersublevel spacings of electrons without any external magnetic field. Epitaxial, complementary-doped and semi-transparent electrostatic gates are grown within the ultra high vacuum conditions of molecular beam epitaxy to voltage-tune the device, while a two dimensional electron gas (2DEG) serves as a back contact. Spacings of the hole sublevels are indirectly calculated from the photoluminescence spectrum by using a simple model given by Warburton et al [1]. Additionally, we observe that the intersubb and resonances of the 2DEG are enhanced due to the quantum dot layer on top of the device.
authors.forename: Shovon
authors.initials: S
authors.lastname: Pal
authors.forename: Sascha R
authors.initials: SR
authors.lastname: Valentin
authors.forename: Nadezhda
authors.initials: N
authors.lastname: Kukharchyk
authors.forename: Hanond
authors.initials: H
authors.lastname: Nong
authors.forename: Alireza B
authors.initials: AB
authors.lastname: Parsa
authors.forename: Gunther
authors.initials: G
authors.lastname: Eggeler
authors.forename: Arne
authors.initials: A
authors.lastname: Ludwig
authors.forename: Nathan
authors.initials: N
authors.lastname: Jukam
authors.forename: Andreas D
authors.initials: AD
authors.lastname: Wieck