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Related papers: Vacuum polarization in graphene with a topological…

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We consider a square lattice configuration of circular gate-defined quantum dots in an unbiased graphene sheet and calculate the electronic, particularly spectral properties of finite albeit actual sample sized systems by means of a…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 A. Pieper , R. L. Heinisch , G. Wellein , H. Fehske

We study the combined effect of a conical topological defect and a Coulomb charge impurity on the dynamics of Dirac fermions in gapped graphene. Beyond a certain strength of the Coulomb charge, quantum instability sets in, which demarcates…

High Energy Physics - Theory · Physics 2015-06-05 Baishali Chakraborty , Kumar S. Gupta , Siddhartha Sen

The occurrence of superconducting and insulating phases is well-established in twisted graphene bilayers, and they have also been reported in other arrangements of graphene layers. We investigate three such arrangements: untwisted AB…

Strongly Correlated Electrons · Physics 2021-08-11 Pierre A. Pantaleon , Tommaso Cea , Rory Brown , Niels R. Walet , Francisco Guinea

Graphene, with its quantum Hall topological (Chern) number reflecting the massless Dirac particle, is shown to harbor yet another topological quantum number. This is obtained by combining Streda's general formula for the polarization…

Mesoscale and Nanoscale Physics · Physics 2015-03-30 Hideo Aoki , Yasuhiro Hatsugai

We analyze the single particle states at the edges of disordered graphene quantum dots. We show that generic graphene quantum dots support a number of edge states proportional to circumference of the dot over the lattice constant. Our…

Mesoscale and Nanoscale Physics · Physics 2010-07-13 M. Wimmer , A. R. Akhmerov , F. Guinea

The Friedel sum rule is extended to deal with topological defects for the case of a graphene cone in the presence of an external Coulomb charge. The dependence in the way the number of states change due to both the topological defect as…

Mesoscale and Nanoscale Physics · Physics 2014-03-24 Baishali Chakraborty , Kumar S. Gupta , Siddhartha Sen

We show that the critical charge for the Dirac excitations in gapless graphene depends on the spatial topology of the sample. In particular, for graphene cones, the effective value of the critical charge can tend towards zero for a suitable…

Mesoscale and Nanoscale Physics · Physics 2011-07-26 Baishali Chakraborty , Kumar S. Gupta , Siddhartha Sen

We study the scattering of graphene quasiparticles by topological defects, represented by holes, pentagons and heptagons. For the case of holes, we obtain the phase shift and found that at low concentration they appear to be irrelevant for…

Strongly Correlated Electrons · Physics 2010-12-17 Jakson M. Fonseca , Winder A. Moura-Melo , Afranio R. Pereira

Graphene's intrinsically corrugated and wrinkled topology fundamentally influences its electronic, mechanical, and chemical properties. Experimental techniques allow the manipulation of pristine graphene and the controlled production of…

Materials Science · Physics 2025-09-09 Fabian L. Thiemann , Patrick Rowe , Andrea Zen , Erich A. Müller , Angelos Michaelides

Based on the tight-binding model calculations and photonic experimental visualization on graphene, we report the domain-wall-induced gapped topological kink states and topological corner states. In graphene, domain walls with gapless…

Mesoscale and Nanoscale Physics · Physics 2020-05-26 Yuting Yang , Ziyuan Jia , Yijia Wu , Zhi-Hong Hang , Hua Jiang , X. C. Xie

Electrons in graphene have fourfold spin and valley degeneracies owing to the unique bipartite honeycomb lattice and an extremely weak spin-orbit coupling, which can support a series of broken symmetry states. Atomic-scale defects in…

Mesoscale and Nanoscale Physics · Physics 2022-08-17 Yu Zhang , Liangguang Jia , Yaoyao Chen , Lin He , Yeliang Wang

Recent studies have focused on laser-induced gaps in graphene which have been shown to have a topological origin, thereby hosting robust states at the sample edges. While the focus has remained mainly on these topological chiral edge…

Mesoscale and Nanoscale Physics · Physics 2016-07-15 D. A. Lovey , Gonzalo Usaj , L. E. F. Foa Torres , C. A. Balseiro

The extraordinary properties of graphene make it a very promising material for use in optoelectronics. However, this is still a nascent field, where some basic properties of the electromagnetic field in graphene must be explored. Here we…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 A. Yu. Nikitin , F. Guinea , F. J. Garcia-Vidal , L. Martin-Moreno

For non-topological quantum materials, introducing defects can significantly alter their properties by modifying symmetry and generating a nonzero analytical index, thus transforming the material into a topological one. We present a method…

Mesoscale and Nanoscale Physics · Physics 2025-07-03 Yuval Abulafia , Amit Goft , Nadav Orion , Eric Akkermans

Nanostructuring of graphene is in part motivated by the requirement to open a gap in the electronic band structure. In particular, a periodically perforated graphene sheet in the form of an antidot lattice may have such a gap. Such systems…

Mesoscale and Nanoscale Physics · Physics 2014-09-09 Stephen R. Power , Antti-Pekka Jauho

Topological materials may exhibit Hall-like currents flowing transversely to the applied electric field even in the absence of a magnetic field. In graphene superlattices, which have broken inversion symmetry, topological currents…

The effects of substrate on electronic and optical properties of triangular and hexagonal graphene nanoflakes with armchair edges are investigated by using a configuration interaction approach beyond double excitation scheme. The…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 W. Sheng , M. Sun , A. Zhou , S. J. Xu

The remarkable electronic properties of graphene have fueled the vision of a graphene-based platform for lighter, faster and smarter electronics and computing applications. One of the challenges is to devise ways to tailor its electronic…

Graphene and carbon nanotubes have extraordinary mechanical and electronic properties. Intrinsic line defects such as local non-hexagonal reconstructions or grain boundaries, however, significantly reduce the tensile strength, but feature…

Materials Science · Physics 2016-07-20 Daniel Berger , Christian Ratsch

Graphene and few-layer graphene at high bias expose a wealth of phenomena due to the high temperatures reached. With in-situ transmission electron microscopy (TEM) we observe directly how the current modifies the structure, and vice versa.…

Mesoscale and Nanoscale Physics · Physics 2013-01-30 Amelia Barreiro , Felix Boerrnert , Mark H. Ruemmeli , Bernd Buechner , Lieven M. K. Vandersypen