Konstantinos Rogdakis

Researcher at CNRS

• France
• October 2006 to June 2015

During my Ph.D I acquired experience in 1D quantum transport both on experimental and theoretical level. My major subject was the experimental and theoretical study of SiC nanowires Field Effect Transistors (NWFETs) devices. In particular, an important part of my research was to develop the entire technological process to integrate SiC NWs into FETs (including AFM topography and e-beam lithography). Apart from the NWs devices fabrication, I also measured and analyzed the electrical behavior of these advanced nanodevices. Thanks to my work, we have been the first group in Europe to publish experimental results of SiC NWFETs for nanoelectronic applications in harsh environments. At the same time, we were the first group in the world who worked on the modeling of 3C-SiC NWFETs operating either in ballistic or in dissipative transport regime. More precisely, we demonstrated numerical simulations of gate-all-around 3C-SiC and Si NWFETs using a full quantum self-consistent Poisson-Schrödinger algorithm within the non equilibrium Green’s functions (NEGF) formalism. Besides, initial experiments on preparing SiC NWs through Si NW carburization were performed opening a new route of growing SiC NWs and nanotubes. The output of the aforementioned study is around 15 papers published in high impact journals and proceedings of international conferences. In the majority of these papers I am the leading author.
During my first post-doc position, my research interests were more physics-oriented. More precisely, I was working on three main projects: a) FET devices based on topological insulators (in particular Bi2Se3 nanoflakes), b) Memristor devices based on LaAlO3/SrTiO3 interfaces and c) ferroelectric properties of capacitors based on superlattices comprised of manganites. Electrical and magnetic characterization of these materials was performed from 2K-300K. Concerning the last project, the main output was the discovery of a new artificial magnetoelectric material based on a superlattice of oxide layers which could be a candidate for future multiferroic based memory devices (Rogdakis et al. Nature Comm. 2012 and Rogdakis et al. APL 2015).
During my second post-doc position, I changed complete the subject working on GaAlAs based spin qu-bits. My duties included the complete design and fabrication of new sample with feature size of approximately 20 nm. The unit cell of these samples is a double quantum dot with a quantum point contact (QPC) close by. I was initially responsible to build an RF reflectometry set up for fast single shot measurements. The reflectometry set up includes a LCR circuit where the resistive part is the resistance of a QPC located close to our quantum dots. Using the spin to charge conversion we were able to measure single shot spin events faster than a microsecond. The goal is to prepare a singlet triplet qu-bit which will serve as a sensor of quantum hall edge states passing next to it. This sample will be used for future experiments on electrons’ (traveling on edge states) interference experiments. The first output of this work is included in the paper ‘V. Thiney, K. Rogdakis et al. 2016 A Spin qu-bit as a fast sensor of quantum Hall effect edge states’ which is almost ready for submission.