Introduction to Magnonics - Fabrication, Spectroscopy and Applications of Nanomagnets

In this module we address the physics and applications of collective spin excitations in magnetic materials that are in the focus of the research field of magnonics. Here, one aims at tailoring spin waves (magnon) at the micro- and nanoscale to transmit and process information without moving charges. This research field has rapidly evolved in recent years fueled also by crossdisciplinary research addressing e.g. photonics and spintronics. It contributes to research on correlated electron systems and possible technological applications thereof. These are issues addressed in the Transregio/SFB TRR80 "From electronic correlations to functionality". In the lecture we will discuss the fabrication and characterization of magnetic devices supporting tailored spin-wave excitations, theoretical models to understand the phenomena and possible applications.   

At the end of the lecture the student has obtained an overview of (i) well-established and recently discovered dynamic phenomena,in magnonics, (ii) state-of-the-art experimental techniques being relevant for exploring spin dynamics from macroscopic to microscopic length scales,  (iii) micromagnetic models, and (iv) fundamental aspects for the control of wave-like excitations in solids. The student will be able to discuss the different contributions to the free energy of magnetic structures entering the equation of motion of spins via effective fields, different classes of relevant magnetic materials, loss mechanisms for collective spin excitations in metallic and insulating ferro/ferrimagnets, basics of microwave technology, relevant frequency regimes, existing and future applications in magnonics.   

Condensed Matter Physics I and II, or Solid state physics, Electrodynamics, Quantum mechanics I, Thermodynamics

The lecture is combined with exercises in which students provide journal club contributions, address specific problems or follow lab visits, etc..

Lecture with presentations using One Note (handwritten notes) and powerpoint 

Books:

A.G. Gurevich and G.A. Melkov, Magnetization Oscillations and Waves, CRC, 1996

D.D. Stancil and A. Prabhakar Spin waves. Theory and applications, Springer, 2009

S.O. Demokritov and A. Slavin (eds) Magnonics from fundamentals to applications Springer, 2013

B. Hillebrands and K. Ounadjela Spin Dynamics in Conned Magnetic Structures I, II, III Topics in Applied Physics vol 83 Springer Berlin Heidelberg

Articles:

M. Krawczyk and D. Grundler, Review and prospects of magnonic crystals and devices with reprogrammable band structure, J. Phys.: Cond. Matter 26, 123202 (2014)

V.V. Kruglyak, S.O. Demokritov, and D. Grundler, Magnonics, J. Phys. D: Appl. Phys. 43, 264001 (2010)

B. Lenk, H. Ulrichs, F. Garbs, and M. Münzenberg, The building blocks of magnonics, Physics
Reports 507, 107 (2011)

In an oral exam the learning outcome is tested using comprehension questions and sample problems.

In accordance with §12 (8) APSO the exam can be done as a written test. In this case the time duration is 60 minutes.