Charge fluctuations in ferroelectric HfO2 (A07*)

• Subject Area: Experimental Condensed Matter Physics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 425217212

Although the stationary properties of ferroelectrics (FEs) can be investigated down to the nanometer scale, dynamic polarisation changes have so far been mainly studied in macroscopic components. In this project, spontaneous charge fluctuations of a single ferroelectric domain on a time scale of nanoseconds will be detected for the first time by employing quantum dots as local reporters of the electric field. The project will focus on the thin-film FE hafnium dioxide (HfO2), in which oxygen vacancies play an important role in stabilising ferroelectricity - and fluctuations could be of greater significance than in traditional FEs. Through targeted material synthesis and spectroscopic characterisation of the point defects, the concentration of different types of oxygen vacancies will be correlated with the emergence of polarisation fluctuations to gain insight into the formation and stabilisation of ferroelectricity.

• DFG Programme: Collaborative Research Centres
• Subproject of: SFB 1432: Fluctuations and Nonlinearities in Classical and Quantum Matter beyond Equilibrium
• Applicant Institution: Universität Konstanz
• Project Heads: Professorin Dr. Martina Müller; Dr. Ron Tenne