Magnon Seebeck effect

• Applicant: Dr. Oleksandr Serha
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2011 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 198250808

The recent observation of the spin Seebeck effect in a magnetic insulator demonstrates the crucial role of collective magnetization excitations, i.e. spin waves and their quanta, magnons, in spin-caloric transport processes, and illustrates the conceptual distinction between this phenomenon and conven-tional thermoelectric generation. The main goal of our project is to uncover the physical mechanisms underlying the Magnon Seebeck effect. The most interesting and important of these is the conversion of a heat flow into a spin voltage in a magnetic insulator. In order to understand the contribution of a thermally activated magnon current to this process, the spatial density distribution and the temporal and spectral characteristics of a magnon gas in a temperature gradient will be thoroughly characte-rized by means of Brillouin light scattering spectroscopy. We will further study the process by which a spin voltage is transformed into an electric voltage by comparing data on magnon currents generated by a temperature gradient in a magnetic insulator with electric voltage measurements in a contiguous paramagnetic metal. Finally, methods to control thermal magnon currents will be developed, and the efficiency of spin Seebeck effect voltage generation will be optimized.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1538: Spin Caloric Transport (SpinCaT)
• Participating Person: Professor Dr. Burkard Hillebrands