Seminar by Dr. Anjan Soumyanarayanan, Magnetic Skyrmions: Spin Topology for Nanoscale Computing

TITLE: 

Magnetic Skyrmions: Spin Topology for Nanoscale Computing

BY:

Dr. Anjan Soumyanarayanan from A*STAR and NUS, Singapore

ABSTRACT:

Magnetic skyrmions are nanoscale, topologically wound spin structures formed by atomic-scale magnetic interactions. Their room temperature (RT) discovery in multilayer thin films has spawned a fascinating research field witnessing rapid progress in fundamental science and device applications [1]. 

In this talk, we first describe the development of a multilayer material platform offering “knobs” to tune skyrmion properties [2]. We show that progressively introducing chiral interactions leads to the emergence of “spin handedness” or helicity, and eventually to thermodynamically stable skyrmions [3]. 

We then turn to skyrmions in nanodots, wherein zero field stability is achieved by confinement [4]. Ongoing efforts are exploring their potential for tunnel junction devices. Finally, we examine skyrmion dynamics in nanowire devices [5]. Here, we identify distinct dynamic regimes, and distinguish intrinsic skyrmion electrodynamics from geometric and disorder-related effects. We will conclude by outlining the promise of skyrmions towards next-generation electronic technologies. 

REFERENCES:

[1]   A. Soumyanarayanan et al., Nature (2016) 539, p509–517.

[2]   A. Soumyanarayanan et al., Nature Materials (2017) 16, p898–904.

[3]   X. Chen et al., In Prep (2019).

[4]   P. Ho et al., Physical Review Applied (2019) 11, 024064.

[5]  A.K.C. Tan, P. Ho et al., In Prep (2019)

BIOGRAPHY:

Anjan Soumyanarayanan is the Programme Head for Spin Technologies at the Agency for Science, Technology & Research (A*STAR) and an Assistant Professor of Physics at the National University of Singapore (NUS). 

Anjan’s research interests are in topological and quantum phenomena at the surfaces and interfaces of thin film materials. His recent work has focussed on spin-orbitronics – including magnetic skyrmions and topological materials. His team develops magnetic thin films and devices and investigates their properties using microscopic, spectroscopic, and transport techniques. 

Anjan obtained his B.A. in Natural Sciences in 2005 from Cambridge University, UK, and PhD in Physics in 2013 from MIT, USA. He recently received the IEEE Magnetics Society Early Career Award and the Singapore Young Scientist Award for his work on skyrmions.