ISBN 9783843940610

978-3-8439-4061-0, Reihe Physik

Fabian Olbrich
Optical and quantum-optical properties of telecommunication-wavelength semiconductor quantum dots on GaAs substrates

245 Seiten, Dissertation Universität Stuttgart (2019), Softcover, A5

Zusammenfassung / Abstract

Driven by the discovery and description of quantum mechanics in the beginning of the 20th century, humanity gained fascinating insight into the world of microscopic particles and phenomena. Alongside the fundamental understanding of this theory, its effects are nowadays supposed to be exploited in order to improve our lifes and technologies, which is a development predicted throughout the so-called second quantum revolution. As future fields of applications, quantum computation and quantum communication are anticipated amongst others. These aspects experience a special kind of attention, as classical media, namely computers and networks, subsequently reach their technological limits. Quantum mechanics offers alternative routes and approaches to generate and process pieces of information, in a way that classical bits can be expanded to become Qubits, e.g. of photonic nature. Motivated by this vision, in particular the characterization of a non-classical photon source states the key topic of this thesis, whereas the approach of semiconductor quantum dots comprising of the promising InAs/GaAs material platform is followed, competing to a variety of materials or different sources. Based on the thereby gained knowledge about the characteristics and properties of the applied structures, approaches may be found to improve the applied devices and methods.

Major preconditions to these emitters to facilitate an implementation into building blocks of quantum networks are a bright, on-demand emission of single, indistinguishable photons, preferably with the option of generating entangled states. In addition, as the calculated data should not only be locally processed, but also be transmitted throughout the network, being compatible to low-attenuation channels forms another main requirement for the photon sources, especially since photons can not be simply amplified or copied. Then again, the latter aspect may compose an advantage of photonic Qubits, as the safety from interception can be guaranteed by fundamental physical limits. For the purpose of low-loss data transmission, the utilization of the telecom O- and C-bands, that feature attenuation minima in optical fibers and dispersion minima or atmospheric transmission windows, respectively, is advantageous and therefore aspired within this thesis.