Nonlinear spin-dependent transport in non-magnetic structures under THz excitation

• Applicant: Privatdozentin Zhanna Gumenyuk-Sychevska, Ph.D.
• Subject Area: Experimental Condensed Matter Physics ; Theoretical Condensed Matter Physics
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 526074932

The proposed research project aims to explore new approaches to detecting the polarization of THz radiation by non-linear spin-dependent photoresponse in non-magnetic narrow gap semiconductor nanostructures and low-dimensional structures, with a view to the future development of novel types of THz detectors. In many modern applications, it is important to be able to detect not only the power, but also the polarization of the THz signal, but terahertz spintronic emitters lack an active material platform for electric-field control. That is why polarization and spin-sensitive detectors of THz frequency are important for applications in the field of characterization of spintronic THz emitters. The present project is focused on the development of comprehensive insight into the physics of non-linear transport phenomena in THz and dc driven hot electron systems including polarization-dependent and spin-dependent effects connected with the reduction of the crystal symmetry in semiconductor structures based on mono- and bilayer graphene, 2DEG and epitaxial layers HgCdTe based bolometers, field effect transistors and Schottky diodes with dual metallic grating and receiving antennas. It proposes the study of nonlinear high-frequency transport as a new and powerful method to access and characterize the electron spin in semiconductors with relativistic fermions system, with an eye on spin optoelectronic applications. The ultimate goal to be achieved during the project performance is the development of the theoretical and experimental background of novel THz semiconductor fast all-electrical detectors allowing spin state detection and separation and predicting the figure of merit of the possible detectors. The planned theoretical studies should lead to a deeper understanding of the fundamental high-frequency nonlinear properties of Dirac fermions in semiconductors. The corresponding experiments will provide immediate verification of the obtained theoretical results, and provide important feedback in the design of samples and setting up of the experiment.

• DFG Programme: WBP Position