π-magnetism and transport in graphene nanostructures
CIC nanoGUNE Seminars
- Speaker
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Thomas Frederiksen, Donostia International Physics Center (DIPC)
- When
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2023/04/03
13:00 - Place
- nanoGUNE seminar room, Tolosa Hiribidea 76, Donostia - San Sebastian
- Add to calendar
-
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**π-magnetism and transport in graphene nanostructures **
Thomas Frederiksen1,2
1 Donostia International Physics Center (DIPC), Donostia-San Sebastián, Spain
2 Ikerbasque, Basque Foundation for Science, Bilbao, Spain
Atomic-scale control over size, shape, and composition of graphene
nanostructures has become a reality through on-surface synthesis whereby
suitably designed precursor molecules are assembled and reacted on a metal
substrate under vacuum conditions. This has led to the realization of
fascinating open-shell nanographenes and nanoribbons with interesting
topological, magnetic, and electron transport properties [1].
In this talk I will provide an overview of the emerging field of π- magnetism
in graphene-based nanostructures and present some of our theoretical
contributions to understand various scanning tunneling microscopy (STM)
experiments [2-5]. The emergence of localized electron spins in such
structures appears promising for applications in quantum technologies,
provided that the interaction between them as well as with their environment
can be controlled. In this regard I will briefly discuss our efforts to
quantify hyperfine interactions to spinful 13C and 1H nuclei, an essential
ingredient to understand electron spin decoherence [6].
Finally, I will present a theoretical study of electron and spin transport in
multi-terminal devices composed of crossed graphene nanoribbons (GNRs) and the
proposal to operate them as spin-polarizing electron beam splitters [7].
[1] D. G. de Oteyza and T. Frederiksen, Carbon-based nanostructures as a
versatile platform for tunable π-magnetism, J. Phys.: Condens. Matter 34,
443001 (2022).
[2] J. Li, S. Sanz, M. Corso, D. J. Choi, D. Peña, T. Frederiksen, and J. I.
Pascual, Single spin localization and manipulation in graphene open-shell
nanostructures, Nat. Commun. 10, 200 (2019).
[3] N. Friedrich, P. Brandimarte, J. Li, S. Saito, S. Yamaguchi, I. Pozo, D.
Peña, T. Frederiksen, A. Garcia-Lekue, D. Sánchez-Portal, and J. I. Pascual,
Magnetism of topological boundary states induced by boron substitution in
graphene nanoribbons, Phys. Rev. Lett. 125, 146801 (2020).
[4] J. Hieulle, S. Castro, N. Friedrich, A. Vegliante, F. Romero Lara, S.
Sanz, D. Rey, M. Corso, T. Frederiksen, J. I. Pascual, D. Peña, On-surface
synthesis and collective spin excitations of a triangulene-based nanostar,
Angew. Chem. Int. Ed. 60, 25224-25229 (2021).
[5] T. Wang, S. Sanz, J. Castro-Esteban, J. Lawrence, A. Berdonces-Layunta, M.
S. G. Mohammed, M. Vilas-Varela, M. Corso, D. Peña, T. Frederiksen, D. G. de
Oteyza, Magnetic interactions between radical pairs in chiral graphene
nanoribbons, Nano Lett. 22, 164-171 (2022).
[6] S. Sengupta, T. Frederiksen, and G. Giedke, Hyperfine interactions in
open-shell planar sp2-carbon nanostructures, arXiv:2303.11422
[7] S. Sanz, N. Papior, G. Giedke, D. Sánchez-Portal, M. Brandbyge, and T.
Frederiksen, Spin-polarizing electron beam splitter from crossed graphene
nanoribbons, Phys. Rev. Lett. 129, 037701 (2022).
**Host:** E. Artacho