Energy gaps in graphene nanomeshes

Oswald, William; Wu, Zhigang

doi:10.1103/physrevb.85.115431

Cited by 77 publications

(72 citation statements)

References 33 publications

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“…We note that in general, the existence and size of the band gap in GALs depends intrically on both the symmetry of the superlattice 33,34 as well as the exact edge geometry of the holes. [35][36][37] In this paper, we consider GAL geometries for which a sizable gap is introduced. We denote the radius of the hole and the side length of the unit cell by R and L, respectively, both of which are measured in units of the graphene lattice constant a.…”

Section: Theory and Methodsmentioning

confidence: 99%

Hofstadter butterflies and magnetically induced band-gap quenching in graphene antidot lattices

Pedersen

2013

Phys. Rev. B

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We study graphene antidot lattices (GALs) in magnetic fields. Using a tight-binding model and a recursive Green's function technique that we extend to deal with periodic structures, we calculate Hofstadter butterflies of GALs. We compare the results to those obtained in a simpler gapped graphene model. A crucial difference emerges in the behavior of the lowest Landau level, which in a gapped graphene model is independent of magnetic field. In stark contrast to this picture, we find that in GALs the band gap can be completely closed by applying a magnetic field. While our numerical simulations can only be performed on structures much smaller than can be experimentally realized, we find that the critical magnetic field for which the gap closes can be directly related to the ratio between the cyclotron radius and the neck width of the GAL. In this way, we obtain a simple scaling law for extrapolation of our results to more realistically sized structures and find resulting quenching magnetic fields that should be well within reach of experiments.

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Section: Theory and Methodsmentioning

confidence: 99%

Hofstadter butterflies and magnetically induced band-gap quenching in graphene antidot lattices

Pedersen

2013

Phys. Rev. B

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“…The recent theoretical studies of graphene nanomeshes [7,10,11,[14][15][16][17][20][21][22] and, in particular, the advances in experimental preparation of such systems [9,12,13,16,18,19] clearly suggest the need for further detailed investigations, in order to elucidate the structures with highest application potential. In this context, we study the magnetic and electronic structure of a dense regular array of pores in graphene, each of the pores being passivated by nitrogen, and doped with a 3d transition metal atom.…”

Section: Introductionmentioning

confidence: 99%

Unravelling the interplay of geometrical, magnetic and electronic properties of metal-doped graphene nanomeshes

Fadlallah¹,

Maarouf²,

Schwingenschlögl³

et al. 2016

J. Phys.: Condens. Matter

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Graphene nanomeshes (GNMs), formed by creating a superlattice of pores in graphene, possess rich physical and chemical properties. Many of these properties are determined by the pore geometry. In this work, we use first principles calculations to study the magnetic and electronic properties of metal-doped nitrogen-passivated GNMs. We find that the magnetic behaviour is dependent on the pore shape (trigonal vs. hexagonal) as dictated by the number of covalent bonds formed between the 3d metal and the passivating N atoms. We also find that Cr and V doped trigonal-pore GNMs, and Ti doped GNMs are the most favourable for spintronic applications. The calculated magnetic properties of Fe-doped GNMs compare well with recent experimental observations. The studied systems are useful as spin filters and chemical sensors.

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“…Other similar scaling rules for structurally modified graphene based on tight-binding or DFT have also been proposed [17][18][19]37 . We expect E g obtained from our GW calculations to also obey the same scaling law (with quantitatively more accurate parameters).…”

Section: A Electronic Band Structuresmentioning

confidence: 99%

“…Certain patterns of defects on graphene induce long-range order that causes a nonzero scattering matrix element between Dirac points and opens a sizable band gap (E g ). The magnitude of E g in these semiconducting materials depends on defect size, type, and distribution [17][18][19][20][21][22][23] .…”

Section: Introductionmentioning

confidence: 99%

Tunable many-body interactions in semiconducting graphene: Giant excitonic effect and strong optical absorption

Dvorak

2015

Phys. Rev. B

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Electronic and optical properties of graphene depend strongly on many-body interactions. Employing the highly accurate many-body perturbation approach based on Green's functions, we find a large renormalization over independent particle methods of the fundamental band gaps of semiconducting graphene structures with periodic defects. Additionally, their exciton binding energies are larger than 0.4 eV, suggesting significantly strengthened electron-electron and electron-hole interactions. Their absorption spectra show two strong peaks whose positions are sensitive to the defect fraction and distribution. The strong near-edge optical absorption and excellent tunability make these two-dimensional materials promising for optoelectronic applications.

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Energy gaps in graphene nanomeshes

Cited by 77 publications

References 33 publications

Hofstadter butterflies and magnetically induced band-gap quenching in graphene antidot lattices

Hofstadter butterflies and magnetically induced band-gap quenching in graphene antidot lattices

Unravelling the interplay of geometrical, magnetic and electronic properties of metal-doped graphene nanomeshes

Tunable many-body interactions in semiconducting graphene: Giant excitonic effect and strong optical absorption

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