Professor Gino Hrkac

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Research Highlights:

Nanoscale switch for vortex polarization mediated by Bloch core formation in magnetic hybrid systems

Adding new functionality to devices, which often requires precise control at the nanoscale, has always been a driving force in research. In a collaboration with scientists at the Paul Scherrer Institute (PSI) and the ETH Zurich, Switzerland and Manchester, UK, we have found a new way to locally switch the orientation of a magnetic feature that is smaller than 20 nm. This discovery provides added control for future technological applications such as data processing, microwave sources or magnetic sensors.

For details see:

P. Wohlhüter, M.T. Bryan, P. Warnicke, S. Gliga, S.E. Stevenson, G. Heldt, L. Saharan, A.K. Suszka, C. Moutafis, R.V. Chopdekar, J. Raabe, T. Thomson, G. Hrkac, L.J. Heyderman, "Nanoscale switch for vortex polarization mediated by Bloch core formation in magnetic hybrid systems." Nat. Commun. 6, 7836 (2015)

http://www.nature.com/ncomms/2015/150804/ncomms8836/full/ncomms8836.html

https://www.youtube.com/watch?v=sdDjS6KMQLQ&feature=youtu.be

Background

I completed my PhD in the Department of Solid State Physics, Vienna University of Technology in 2005, studying eddy current effects in magnetic nanomaterials and the­ir influence on high frequency magnetisation behaviour. ­

­2005 I joined the Department of engineering Materials at the University of Sheffield. I was developing a finite element model to treat non linear magnetisation dynamics to investigate high frequency switching and spin torque effects in magnetic nano pillars and magnetic Tunnel Junction systems.

In 2009 I was awarded the Royal Society University Research Fellowship and the WWTF High Potential Award from the Vienna Science and technology Fund.

In 2012 I joined the University of Exeter as an associate Professor in Functional Materials.

In December 2016 Awarded Personal Chair in Applied theoretical and computational Solid-state physics

Research interests

My main research area is computational and theoretical magnetism, and especially the development of a numerical model to investigate and predict the behaviour of magnetic spin valve systems and the effect of eddy currents in nano-scale materials. In particular I am working on the theoretical and numerical description of spin electronic devices on a length scale ranging from the computation of the local spin current density and magnetization dynamics with a sub-nm resolution in micron size devices (magnetic nano pillars and Magnetic Tunnel Junctions).

A prominent example for my work is the theoretical explanation of the angular dependency of phase locking phenomena in point contacted spin valves and my work on the simulation of spin current induced magnetization dynamics that explained the low frequency oscillations found in point contact devices that were explained by vortex oscillations.

My latest research includes ab initio simulations of atomic structures, solid state molecular dynamics for the simulation of the transition of amorphous to crystalline grain boundaries in NdFeB magnets within the framework of an industrial funded project on permanent magnets (European-Japanese consortium) and the coupling of the spin-diffusion equation with the Landau-Lifshitz-Gilbert equation.

Key projects

• EPSRC Heat induced phase change exchange coupled composite media (HIP-ECC) Joint Project with Prof Thomson, University of Manchester

• Royal Society University Research Fellowship, Fundamentals of spin-torque induced magnetisation dynamics

• WWTF, Micromagnetic Simulations and Computational Design of Future Devices

• Toyota Motor Corporation, Fundamental understanding of boundary phases between magnetic grains in permanent magnets

• EPSRC Bridging the Gaps, Pump-Priming Award,Ferrofluid-based microscale dosage device

• COST Action P19 Multiscale modelling of Materials

• BRITISH-ITALIAN PARTNERSHIP PROGRAMME, Nanotechnology: Programmable Lab on a Chip

Research group

• Dr Lalita Saharan (Senior research fellow)

• Dr Matthew Bryan (Senior research fellow)

• Dr Thomas Ostler (Senior research fellow)

Former Research group members:

• Dr Rene Dost (Senior research fellow)

• Mr Alexander Steiner (Student)