Physics / Fizik

Permanent URI for this collectionhttps://hdl.handle.net/11147/6

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  • Article
    Citation - WoS: 7
    Citation - Scopus: 7
    Effects of Random Atomic Disorder on the Magnetic Stability of Graphene Nanoribbons With Zigzag Edges
    (American Physical Society, 2018) Çakmak, Korhan Ertan; Altıntaş, Abdulmenaf; Güçlü, Alev Devrim
    We investigate the effects of randomly distributed atomic defects on the magnetic properties of graphene nanoribbons with zigzag edges using an extended mean-field Hubbard model. For a balanced defect distribution among the sublattices of the honeycomb lattice in the bulk region of the ribbon, the ground-state antiferromagnetism of the edge states remains unaffected. By analyzing the excitation spectrum, we show that while the antiferromagnetic ground state is susceptible to single spin-flip excitations from edge states to magnetic defect states at low defect concentrations, its overall stability is enhanced with respect to the ferromagnetic phase.
  • Article
    Citation - WoS: 16
    Citation - Scopus: 16
    Magnetic Phases of Graphene Nanoribbons Under Potential Fluctuations
    (American Physical Society, 2016) Özdemir, Hakan Ulaş; Altıntaş, Abdulmenaf; Güçlü, Alev Devrim
    We investigate the effects of long-range potential fluctuations and electron-electron interactions on the electronic and magnetic properties of graphene nanoribbons with zigzag edges using an extended mean-field Hubbard model. We show that electron-electron interactions make the edge states robust against potential fluctuations. When the disorder is strong enough, the presence of electron-hole puddles induces a magnetic phase transition from antiferromagnetically coupled edge states to ferromagnetic coupling, in agreement with recent experimental results.