University of Groningen
Graphene heterostructures for spin and charge transport
Zomer, Paul Joseph
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Publication date: 2019
Link to publication in University of Groningen/UMCG research database
Citation for published version (APA):
Zomer, P. J. (2019). Graphene heterostructures for spin and charge transport. University of Groningen.
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Propositions
accompanying the thesis
Graphene heterostructures for spin and charge transport
by Paul Zomer
1. In graphene heterostructure fabrication, one should try alternative boron nitride or graphite sources as this may strongly affect the exfoliated flake geometry.
2. The difficulty in heterostructure fabrication lies not in placing two micrometer sized crystal flakes on top of each other, but in cleaning their surfaces of polymer residue afterwards.
3. Heterostructure fabrication by picking up crystal flakes one by one saves a considerable amount of time and allows for clean interfaces. With the rising interest in other layered materials and their controlled interaction with each other, this will remain a key method for years to come.
4. The most unambiguous way to demonstrate a long spin relaxation length is by measuring the decay of a spin signal over distance. However, as spin transport continues to be enhanced in high quality graphene, the flake size will become a limitation.
5. To increase the distance over which a spin signal can travel in graphene, it is easiest to improve the charge carrier mobility.
6. Few layer graphene deserves more attention where spin transport is concerned due to its robustness to external factors. On top of that, irradiation can even be used to enhance spin transport by improvement of the spin lifetime and contact polarization.
7. The right combination of creativity, dexterity, patience and sticky tape is very important when working with graphene heterostructure devices.
8. Boron nitride is widely used in cosmetics. As graphene research shows, it can even be used to make measurement data look nicer.
9. Following instructions in a process is convenient. However, the potential lack of understanding of what is done may lead to unforeseen problems and ultimately limits what can be achieved.
10. Time appears to pass faster the more things need to be done. This unfortunately does not mean that things are done faster.
