Highly Anisotropic Dirac Fermions in Square Graphynes

Zhang, L. Z.; Wang, Z. F.; Wang, Zhiming M.; Du, Shixuan; Gao, Hongjun; Liu, Feng

doi:10.1021/acs.jpclett.5b01337

Cited by 77 publications

(55 citation statements)

References 38 publications

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“…Theoretical studies [42][43][44] have shown that strain can significantly alter the electronic band structure of graphene i.e., change its noninteracting single particle properties and create anisotropic Dirac fermions which are also found in other solid state systems [45][46][47][48][49][50][51] . Due to such a directional dependent nature of charge carriers, the anisotropic Dirac fermions can find possible applications in low-dimensional devices utilizing anisotropic charge transport and therefore it is of utmost importance to understand their basic properties.…”

Section: Introductionmentioning

confidence: 99%

Excitonic mass gap in uniaxially strained graphene

Sharma¹,

Kotov²,

Neto³

2017

Phys. Rev. B

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We study the conditions for spontaneously generating an excitonic mass gap due to Coulomb interactions between anisotropic Dirac fermions in uniaxially strained graphene. The mass gap equation is realized as a self-consistent solution for the self-energy within the Hartree-Fock meanfield and static random phase approximations. It depends not only on momentum, due to the long-range nature of the interaction, but also on the velocity anisotropy caused by the presence of uniaxial strain. We solve the nonlinear integral equation self-consistently by performing large scale numerical calculations on variable grid sizes. We evaluate the mass gap at the charge neutrality (Dirac) point as a function of the dimensionless coupling constant and anisotropy parameter. We also obtain the phase diagram of the critical coupling, at which the gap becomes finite, against velocity anisotropy. Our numerical study indicates that with an increase in uniaxial strain in graphene the strength of critical coupling decreases, which suggests anisotropy supports formation of excitonic mass gap in graphene.

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Section: Introductionmentioning

confidence: 99%

Excitonic mass gap in uniaxially strained graphene

Sharma¹,

Kotov²,

Neto³

2017

Phys. Rev. B

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“…These materials can host Dirac cones that give rise to rich physical properties [2,[9][10][11]. Recent theoretical investigations for new Dirac materials in simple two-dimensional structures have attracted great attention [12][13][14][15][16], whereas experimental observations of Dirac cones beyond the honeycomb structure are still rare.…”

mentioning

confidence: 99%

Dirac Fermions in Borophene

et al. 2017

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Honeycomb structures of group IV elements can host massless Dirac fermions with non-trivial Berry phases. Their potential for electronic applications has attracted great interest and spurred a broad search for new Dirac materials especially in monolayer structures. We present a detailed investigation of the β12 boron sheet, which is a borophene structure that can form spontaneously on a Ag(111) surface. Our tight-binding analysis revealed that the lattice of the β12-sheet could be decomposed into two triangular sublattices in a way similar to that for a honeycomb lattice, thereby hosting Dirac cones. Furthermore, each Dirac cone could be split by introducing periodic perturbations representing overlayer-substrate interactions. These unusual electronic structures were confirmed by angle-resolved photoemission spectroscopy and validated by first-principles calculations. Our results suggest monolayer boron as a new platform for realizing novel high-speed low-dissipation devices.

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“…Besides hexagons that form the TSM carbon structures, recent studies on 2D carbon materials show that the other member rings can also generate TSM carbon, and bring versatile properties . Hence, we naturally wondered if a 3D TSM carbon can be designed by taking the other member rings as the building blocks.…”

mentioning

confidence: 99%