Team

Group leader: PD Dr. Alexander Pawlis

My team and I are interested in fabricating and studying nano-structured devices for optical quantum communication. We take a holistic approach starting with molecular beam epitaxy of heterostructures, top-down and bottom-up nano processing of the devices, to electrical and quantum optical characterization of the prototypes.

Scientific Staff

My main research focuses on the design and fabrication of shadow wall structures, a critical architecture for the Shadow Wall epitaxy technique. I engineer these nanoscale shadow masks to control material deposition, enabling the full in-situ growth of advanced II-VI and III-V semiconductor devices with complex geometries.
Furthermore, I develop high-efficiency sources of indistinguishable single photons, essential for reliable quantum computing and long-range communication. My work investigates isolated impurity states in epitaxial II-VI nanostructures to achieve the precise emission of single photons with ultra-short radiative lifetimes.

I am involved in the development and optimization of different semiconductor systems for novel devices in the field of quantum communication. Specifically, I use molecular beam epitaxy (MBE) to grow and combine several III-V and II-VI compound semiconductors such as (Al)GaAs and Zn(Mg,Cd)Se and to understand their properties.

Technical Staff

As the technician of the Nanocluster I am responsible for the whole UHV cluster tool and the lab safety. My focus is to keep everything running so the scientist can focus on their growth experiments.

My responsibilities include technical support of the nanocluster, fabrication of semiconductor layers on the III/V MBE's and of contact layers in the Balzers evaporation chamber.

My task is the supervision and management of the PL laboratories of the institute. I support the work of the students, instruct them in the use of the equipment and optimize the experiments. My focus is in the field of optics, laser and fiber technology.

PhD students

In my PhD thesis, I am working towards the realization of solid-state qubits with an optical interface in our II/VI material system. On one hand, I am investigating the quantum-optical properties of our already well-established ZnSe-based single-photon sources regarding their application as optically controlled qubits. On the other hand, we are currently developing an all-in-situ ZnSe-based FET-platform that will serve as the basis for gate defined, i.e., electrostatically controlled qubits.

My PhD project focusses on Josephson junctions in nanowires. The nanowires are grown laterally using molecular beam epitaxy (MBE). The superconductor is deposited directly after using our shadow wall epitaxy process. Then, I perform low-temperature measurements to characterize the nanowire and the Josephson junction. 

As part of my doctoral thesis, I am working on the realisation of piezoelectrically-controlled photon Bose-Einstein condensates in a scalable on-chip platform. To this end, I am growing III-V semiconductor-based heterostructures using molecular beam epitaxy, which I subsequently characterise using optical methods in order to optimise the growth process.

Bachelor's and Master's students

In my master’s project, I investigate unconventional dielectric barrier materials for superconducting Josephson junctions to reduce losses and improve coherence in quantum computing devices. I synthesize thin films, characterize their electrical properties, and fabricate a Josephson junction using stencil lithography to evaluate the materials directly in a functional device.