Opportunities
Open positions in the ‘Magnetism and Spin Electronics Group’ at Trinity College Dublin
The group has secured contracts for two new projects and are currently looking to take on a post-doc and two PhD students.
‘TRANSPIRE’, funded by the European Commission through the FET-OPEN scheme, will run for four years. The project aims to develop new chip-based spin-torque nano-oscillators that will advance electronics into the previously inaccessible terahertz frequency domain, thereby sustaining the big data revolution for another 25 years [1]. The key here is the ability of thin-film trilayer stacks to exhibit an oscillating magnetotesistance when a spin-polarized electric current transfers angular momentum from one magnetically-ordered electrode to the other, thereby exciting Larmor precession. The frequency of oscillation is determined by the effective anisotropy field in the Kittel equation for magnetic resonance. The discovery [2] of the Group in 2014 of the first experimental zero-moment half metal (Mn2Ru0.5Ga) ‘MrG’ where the anisotropy field diverges at compensation allows this effective field to be tuned continuously close to compensation to attain frequencies ranging from hundreds of GHz up to a few THz. The project is a collaboration between TCD and two German groups (A. Deac and M. Gensch of the Helmholtz Zentrum Dresden), a theory group in Norway (A. Brataas, NTNU, Trondheim) and a Swiss industrial partner (Swissto12, Lausanne).
The second project associates research centres in Ireland and the USA; it is jointly funded by Science Foundation Ireland (SFI), The Department of Learning – Northern Ireland (DLNI) and the US National Science Foundation (NSF). The project targets energy consumption during switching of magnetic elements for data storage. A promising way to combine high switching speeds with low energy consumption relies on voltage control of magnetic anisotropy. The set of manganese-based ferrimagnets (Mn3-xGa, Mn3Ge, Mn2FeGa) previously developed by the Group have many of the necessary requirements, including a high anisotropy constant coupled with a low density of states at the Fermi level and crucially a high degree of spin polarisation necessary to achieve high magnetoresistance. Partners here are UC Berkley (Ramesh) UCLA (Kang Wang) and QUB (Solveig Felton, Marty Gregg).
Thin film stacks will grown by sputtering or pulsed laser deposition in a new 3M€ multi–chamber deposition tool (delivery expected end 2017). Prior experience with thin film sample deposition is therefore expected. The post-doctoral researcher should have experience of magnetic thin film devices, fast magneto-optics or ferromagnetic resonance. The films and devices will be extensively characterized in-house, and in large-scale European facilities. The magnetisation dynamics will be probed by cavity and strip-line FMR and by time-resolved MOKE. Prior experience with fast optics would be an advantage.
One PhD student will work closely with the postdoc, the other will have a focus on materials growth and characterisation. A successful candidate will have a good a bachelor’s degree in experimental or theoretical physics or materials science.
The postdoc position is initially for 2 years, at 40 – 48k€, whereas the PhD position is funded for the 4 years duration of the degree at 16 – 18k€ plus fees.
[1] D. Betto, et al., ‘The zero–moment half metal: How could it change spin electronics?’, AIP Adv., vol. 6, no. 5, pp. 055601, 2016. [2] H. Kurt, et al., ‘Cubic Mn2Ga Thin Films: Crossing the Spin Gap with Ruthenium’, Phys. Rev. Lett., vol. 112, no. 2, pp. 027201, 2014.
For further information please contact stamenop@tcd.ie, rodek@tcd.ie or jcoey@tcd.ie