Magnetic resonance in semiconductors

• Applicant: Dr. Vladislav Kataev
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2008 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 39338622

In the second funding period we will continue electron spin resonance (ESR) studies aimed at the understanding of the long-living spin coherent electron states in III/V semiconductors and semiconductor heterostructures, such as GaAs. Along with using advanced but yet traditional ESR techniques based on the direct detection of the absorbed microwave radiation at the resonance, we will also focus on the electrically detected ESR (EDMR) schemes with the possibility of optical pumping. This approach will yield a strong increase of the sensitivity which is particularly important for studies of heterostuructures with small spin concentration. A combination of conventional ESR and EDMR techniques will enable complementary insights into the spin-dephasing and spin relaxation processes in particular regarding the interplay between optically excited spin-polarized electrons and donor states, impurities and dislocations. The influence of the carrier concentration on the spin coherence will be examined by studying sets of samples with different chemical doping but also in heterostructures where the electron concentration is controlled by the gate voltage. Finally, the spin properties of graphene will also be addressed by ESR and EDMR. Here the experiments will focus on the understanding of the relation between a very peculiar electronic structure and the dominant spin-spin interactions and relaxation paths of electrons in graphene.

• DFG Programme: Research Units
• Subproject of: FOR 912: Coherence and Relaxation Properties of Electron Spins
• Participating Person: Professor Dr. Bernd Büchner