Electron spin transport in graphene-based devices

  Welcome on the research webpage of Thomas Maassen.

  Below you can find some information on my research in nanophysics.

  (On www.tomlizard.com you can find my photography
  and here some info on what happened in my life since I finished my PhD research.)


 
Thomas Maassen

Burnaby BC
Canada


In 2013 I finished working at the University of Groningen (NL) where I did my PhD in solid state physics in the group of Bart van Wees, Physics of Nanodevices. My defense was on the 3rd of May 2013 in Groningen (see here). You can find my thesis here.

In my research I examined the spin transport properties of graphene. Spin transport belongs to the field of spintronics in which the magnetic moment of an electron, the spin, is used to transport and store information. Graphene is a truly two dimensional material as it consists of a one atom thick honeycomb lattice of carbon atoms.
More information on these topics can be found here: Spintronics, Graphene.

Before I started my PhD I worked at the RWTH Aachen in the group of Gernot Güntherodt and Bernd Beschoten on my Diplom project (similar to a MSc). I researched the spin transfer torque effect and current-induced magnetization dynamics in ferromagnetic nanostructures.


Several scientific articles reporting on my research are published:

T. Maassen, J. J. van den Berg, E. H. Huisman, H. Dijkstra, F. Fromm, T. Seyller, and B. J. van Wees, "Localized States Influence Spin Transport in Epitaxial Graphene", Phys. Rev. Lett. 110, 067209 (2013) (arXiv - free online version), press release.

M. Wojtaszek, I. J. Vera-Marun, T. Maassen, and B. J. van Wees, "Enhancement of spin relaxation time in hydrogenated graphene spin valve devices", Phys. Rev. B 87, 081402(R) (2013) (arXiv - free online version).

T. Maassen, I. J. Vera-Marun, M. H. D. Guimarães, and B. J. van Wees, "Contact induced spin relaxation in Hanle spin precession measurements", Phys. Rev. B 86, 235408 (2012) (arXiv - free online version).

M. H. D. Guimarães, A. Veligura, P. J. Zomer, T. Maassen, I. J. Vera-Marun, N. Tombros, and B. J. van Wees, "Spin Transport in High-Quality Suspended Graphene Devices", Nano Letters 12 (7), 3512 (2012) (arXiv - free online version), press release.

T. Maassen, J. J. van den Berg, N. IJbema, F. Fromm, T. Seyller, R. Yakimova, and B. J. van Wees, "Long Spin Relaxation Times in Wafer Scale Epitaxial Graphene on SiC(0001)", Nano Letters 12 (3), 1498 (2012) (arXiv - free online version), press release.

T. Maassen, F. K. Dejene, M. H. D. Guimarães, C. Józsa, and B. J. van Wees, "Comparison between charge and spin transport in few-layer graphene", Phys. Rev. B 83, 115410 (2011) (arXiv - free online version).

C. Józsa, T. Maassen, M. Popinciuc, P. J. Zomer, A. Veligura, H. T. Jonkman, and B. J. van Wees, "Linear scaling between momentum and spin scattering in graphene", Phys. Rev. B 80, 241403(R) (2009) (arXiv - free online version).


Articles posted online but not published in scientific journals:

N. Müsgens, S. Fahrendorf, T. Maassen, A. Heiss, J. Mayer, B. Özyilmaz, B. Beschoten, and G. Güntherodt, "Frequency domain studies of current-induced magnetization dynamics in single magnetic-layer nanopillars", online link: arXiv:1201.2268

N. Müsgens, T. Maassen, E. Maynicke, S. Rizwan Ali, A. Heiss, R. Ghadimi, J. Mayer, G. Güntherodt, and B. Beschoten, "Intermediate state switching dynamics in magnetic double layer nanopillars grown by molecular beam epitaxy", online link: arXiv:1201.2752


Additional to scientific articles I also co-wrote an article in a Dutch science magazine:

J. J. van den Berg, T. Maassen, and B. J. van Wees, "Spins in epitaxiaal grafeen leven langer", Nederlands Tijdschrift voor Natuurkunde, August 2012, p. 304 (Dutch).



During my PhD research I attended numerous scientific conferences and visited other research groups to present my results. In July 2011 I was member of the international advisory committee for the workshop "Spintronics in Graphene" in Singapore.

Below a list of selected scientific presentations:

seminar: Spin transport in graphene based devices, Universität Regensburg, Regensburg, Germany, June 2012

invited talk: Long spin relaxation times in epitaxial graphene on SiC(0001), Conference, DPG Spring meeting 2012, Berlin, Germany, Mar 2012

invited talk: Long spin relaxation times in epitaxial graphene on SiC(0001), 2nd Novel Materials Symposium hosting the DFG SPP1285 International Workshop on Spin and Quantum Transport, Berlin, Germany, Mar 2012

talk: Long spin relaxation times in epitaxial graphene on SiC(0001), Workshop, Graphene Synthesis and Characterisation for Applications, Windermere, UK, Nov 2011

seminar: Long spin relaxation times in epitaxial graphene on SiC(0001), RWTH Aachen, Aachen, Germany, Nov 2011

invited talk: Long spin relaxation times in epitaxial graphene on SiC(0001), Workshop, 3rd International Symposium on the Science and Technology of Epitaxial Graphene, St. Augustine, Florida, USA, Oct 2011

seminar: Spin transport in graphene based devices, University of British Columbia, Vancouver, Canada, Aug 2011

invited talk: Spin transport in graphene based devices, Workshop, Spintronics in Graphene, Singapore, Singapore, July 2011

talk: Spin transport in single and few layer graphene, Conference, Graphene Brazil, Belo Horizonte, Brazil, Dez 2010

talk: Spin transport in few layer graphene, Workshop, 2nd International Symposium on the Science and Technology of Epitaxial Graphene, Amelia Island, Florida, USA, Sep 2010

talk: Comparison of spin and charge diffusion in graphene, Graphene day, Nijmegen, The Netherlands, Aug 2009