Spintronics with chiral helimagnetic insulators

• Applicant: Aisha Aqeel, Ph.D.
• Subject Area: Experimental Condensed Matter Physics
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 528001743

Spintronics with helimagnetic insulators (SpinLEGO) aims to foster the functionalization of helimagnetic materials for energy-efficient hybrid quantum magnonics. The twisting of the magnetic textures in these materials may be topologically trivial or nontrivial in nature, but universally collective magnetic excitations at frequencies ranging from a few GHz to several THz are observed. A key goal of SpinLEGO is the identification of helimagnets with ultralow magnetic damping and strong coupling to microwave photons, as rendered possible by an in-depth understanding of the underlying magnetization dynamics. To pave the way for helimagnetic insulators with purpose-designed magnetization dynamics, SpinLEGO comprises five primary objectives: (1) Development of methods for the single-crystal growth of high-purity helimagnets with optimized magnetic damping. (2) Application of nanostructuring and interface engineering to modify the magnetic properties of the single crystals. Using neutron and resonant x-ray elastic scattering techniques, we will study these interface-engineered heterostructures focusing on the static and dynamic magnetic properties emerging at the surface of bulk helimagnets. (3) Detection and quantitative description of incoherent-to-coherent magnetic excitations. We will combine the use of thermally and electrically excited magnons through spin pumping and measurements of the inverse spin-Hall effect in local and nonlocal device geometries. (4) Control and detection of coherent magnons in helimagnets. (5) Tailoring the magnetization dynamics of helimagnets by combining them with topologically trivial magnets. In summary, the SpinLEGO project will discover new magnetic systems for hybrid quantum magnonics using coherent magnetic excitations in helimagnets.

• DFG Programme: Independent Junior Research Groups
• International Connection: China, Israel, Netherlands, USA
• Major Instrumentation: Cryogen-free 3D vector magnet
• Instrumentation Group: 8550 Spezielle Kryostaten (für tiefste Temperaturen)
• Cooperation Partners: Professor Dr. Lucas Caretta; Professor Dr. Guowei Li; Professor Dr. Thomas Palstra; Professor Dr. Yossi Paltiel