Spintronics with antiferromagnets and phonons (SHARP)

• Applicant: Professorin Dr. Olena Gomonay
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 397322108

The proposed research project aims to open and explore new ways to detect and manipulate antiferromagnets using phonons and magneto-elastic coupling effects. Antiferromagnetic spintronics is a young and very active research field that focuses on the active control and manipulation of antiferromagnets. Devices based on antiferromagnets provide many features necessary to increase energy efficiency, connectivity, and information security. Antiferromagnetic-based memory cells are non-volatile and can potentially use lower energy in the read/write process due to their natural fast switching in the Teraherz range. This natural frequency of antiferromagnets also expands the range of bandwidths for communication. In addition, antiferromagnets are silent in the electromagnetic range, thus protecting the encoded information from an unauthorised access. Such a silence, while being useful for information security, hampers direct observation and hence control of antiferromagnetic devices, as well as cross-talk between them. SHARP's goal is to hear the voice of antiferromagnets, to learn how to talk to them and how to make them communicative. We will do this by using the phonons, which are typically strongly coupled with the magnetic subsystem in antiferromagnets. We will model how to obtain, transfer and deliver readable information about the real-time behaviour of antiferromagnetic bits via phonons. Such a spin-mechanical interface will open also new ways for detection of antiferromagnetic states at nanoscales and for effective control and manipulation of antiferromagnetic textures and skyrmions. Our analytical approach will be supported by micromagnetic simulations mainly using the MUMAX 3 and OMNeS software. OMNeS, a software specially designed for the description of antiferromagnets under the action of different spin torques, is now being developed by our group. We will further incorporate magneto-elastic interactions and elastic degrees of freedom in the simulations in order to characterise the effect of magnon-phonon coupling on the spin-current-induced dynamics of antiferromagnetic nanoparticles and textures. We will develop the concept of phonon currents as a tool for visualisation, manipulation and communication between antiferromagnetic nanoparticles and skyrmions.The integration of phonons as important constitutive elements of antiferromagnetic spintronics will naturally yield new physical regimes and new functionality of antiferromagnetic-based devices.

• DFG Programme: Research Grants
• Co-Investigator: Professor Jairo Sinova, Ph.D.