THz and subTHz Excitations in Graphene Based Materials: Magneto-Optical Studies

• Applicant: Dr.-Ing. Petr Neugebauer, Ph.D.
• Subject Area: Experimental Condensed Matter Physics ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: from 2014 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 262040769

This project aims to achieve a detailed understanding of the low-energy electronic structure of graphene based materials prepared by different methods such as epitaxial growth, CVD, exfoliation or decoupled graphene from bulk graphite. This will be done by magneto-optical studies in the THz- and sub-THz region using infrared and high frequency electron paramagnetic resonance spectrometers, respectively, both in frequency and magnetic field domains. We propose the first systematic comparative study of graphene specimens, which differ by substrate, defects, size and grain boundaries etc. Noninvasive low-energy (0.4-40 meV) experimental methods will bring decisive information about limits of intrinsic charge mobility, the electronic band structure (Fermi surface) and other phenomena, like confined plasmons, magnetic excitations etc. The low-energy excitations will be followed as a function of numbers of layers, to map and understand the change in electronic properties going from monolayer to bulk graphite. We will also perform the first microwave magneto-absorption measurements in gated graphene flakes with the aim to control confined plasmon frequency. This will be the first step towards optoelectronic devices.

• DFG Programme: Research Grants
• International Connection: France, USA
• Participating Persons: Privatdozent Dr. Denis Basko; Professor Dr. Lapo Bogani; Professor Dr. Martin Dressel; Dr. Jan Kunc; Dr. Milan Orlita