Advent calendar - December 23rd - Nele Harnack

In the Zernike Institute Advent Calendar, we are presenting 24 short spotlights in December. In these specials, we highlight PhD students, postdocs, support staff and technicians of our research groups and team - providing a glimpse in their typical day at work. In Episode 23 meet Nele Harnack, external PhD student in the Solid State Materials for Electronics (SSME) group under the supervision of Prof. Beatriz Noheda, and within both the Zernike Institute and the CogniGron center. Most of the time, she works in the Physics and Science of Information Group at IBM Research under the supervision of Dr. Bernd Gotsmann.

I am an external PhD student in the Solid State Materials for Electronics (SSME) group under the supervision of Prof. Beatriz Noheda, and within both the Zernike Institute and the CogniGron center. Most of the time, I work in the Physics and Science of Information Group at IBM Research under the supervision of Dr. Bernd Gotsmann. Both institutions come together in the EU-project “Materials for Neuromorphic Circuits” (MANIC), of which the title might explain itself: we focus on investigating new materials that have intrinsic nanoscale properties which can be utilised for devices in neuromorphic computing, inspired by biological functionality of neurons and aiming at more energy-efficient computing.

My research focuses on thermal aspects of neuromorphic devices – vanadium-dioxide-based self-oscillators and hafnia-based resistive-switching RAM – whose behaviour is strongly modulated by the temperature they reach through self-heating. Yet, the temperature distribution within them is often not well understood, especially at the nanoscale. Therefore, in my work, I investigate these devices with Scanning Thermal Microscopy, with which we can measure the surface temperature of films and devices at the nanoscale.

Doing this involves an exciting mix of daily activities: designing and then fabricating devices in the cleanroom, preparing and inserting them into our measurement setup, conducting self-heating experiments, post-processing and analysis of data. Last but not least, it involves many discussions and collaborations with my colleagues and supervisors at IBM and also during exchanges and whilst hosting exchange students. These are so fulfilling, since it is so helpful to discuss interdisciplinary research with as many different researchers as possible, but also because of how many genuinely nice, diverse and interesting people I have met. During my 5 week stay at the UG, I got to know the SSME group and research at UG, working with conductive Atomic Force Microscopy on PLD-grown oxide thin films. Through MANIC, which is a consortium with research institutions across Europe and 15 PhD students, I also had the opportunity for a research stay at the group of Prof. Marty Gregg ( at QUB-Belfast), discussing implementation of quantitative Scanning Thermal Microscopy and learning about even more different oxide materials.

I wish everyone a nice Christmas break from their research – which I hope is as exciting to them as mine is to me – and a good start for the coming year!

See all Advent Calendar items 2024 here!