Dresden 2017 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 87: Carbon: Diamond and others
HL 87.6: Talk
Friday, March 24, 2017, 11:15–11:30, POT 06
Wigner crystallization in graphene nanoribbons with zigzag edges — •Alev Devrim Guclu — Izmir Institute of Technology, Izmir, Turkey
We investigate the Wigner crystallization of electrons and holes at the zigzag edges of graphene nanoribbons using many-body configuration interaction method. We show that Wigner crystallization occurs at a surprisingly high electronic density of ∼ 0.8 nm−1. In contrast with one-dimensional electron gas, the flat-band structure of the edge states makes the system interaction dominated, facilitating the electronic localization. The Wigner localization is found to affect strongly the magnetic coupling between the nearest neighbor electrons, causing an antiferromagnetic-ferromagnetic phase transition. As the width of the ribbon is decreased to 11 Å, interedge coupling becomes important, hence increased kinetic energy overcomes the long-range Coulomb repulsion and suppresses the Wigner crystallization. Finally, we show that Wigner crystallization can also occurs for holes, albeit weaker than for electrons. This work was supported by The Scientific and Technological Research Council of Turkey (TUBITAK) under the 1001 Grant Project Number 114F331.