Edge state modulation of bilayer Bi nanoribbons by atom adsorption

Chen, Li; Cui, Guangliang; Zhang, Pinhua; Wang, Xiaoli; Li, Hongmei; Wang, Dongchao

doi:10.1039/c4cp02213k

Cited by 19 publications

(16 citation statements)

References 30 publications

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“…As a result, in the Bi bilayer composed of the heaviest group-V element, the spin-orbit coupling is so strong to induce a band inversion between the conduction and valence bands and the formation of a TI phase [see Figs. 5(b) and (c)] [146,149,[151][152][153][154][155]. Recently, the time-reversal symmetry-protected edge states have been experimentally observed in an exfoliated Bi (111) bilayer [160], and in a Bi bilayer on a substrate, e.g.…”

Section: Bismuth Bilayermentioning

confidence: 99%

Topological phases in two-dimensional materials: a review

Ren¹,

2016

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Topological phases with insulating bulk and gapless surface or edge modes have attracted much attention because of their fundamental physics implications and potential applications in dissipationless electronics and spintronics. In this review, we mainly focus on the recent progress in the engineering of topologically nontrivial phases (such as Z2 topological insulators, quantum anomalous Hall effects, quantum valley Hall effects etc.) in two-dimensional material systems, including quantum wells, atomic crystal layers of elements from group III to group VII, and the transition metal compounds.

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Section: Bismuth Bilayermentioning

confidence: 99%

Topological phases in two-dimensional materials: a review

Ren¹,

2016

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“…The discovery generates extensive attentions in the QSH phase on group-V monolayers and the related applications in topological devices [26][27][28] . Furthermore, it is found that the topological characteristics of group-V monolayers can easily be modified by doping, adsorption, chemical modification or substrate effect [29][30][31][32][33][34][35][36][37][38] . For example, the first-principles calculations have demonstrated that the magnetic doping or substrate can induce very large exchange fields (up to 400 meV) in the functionalized bismuthene 39 and antimonene 40,41 , which drives the system from the QSH phase to quantum anomalous Hall and valley polarized QSH phases, respectively.…”

Section: Introductionmentioning

confidence: 99%

Engineering a topological quantum dot device through planar magnetization in bismuthene

Zhou

Cheng

et al. 2019

Phys. Rev. B

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The discovery of quantum spin Hall materials with huge bulk gaps in experiment, such as bismuthene, provides a versatile platform for topological devices. We propose a topological quantum dot (QD) device in bismuthene ribbon in which two planar magnetization areas separate the sample into a QD and two leads. At zero temperature, peaks of differential conductance emerge, demonstrating the discrete energy levels from the confined topological edge states. The key parameters of the QD, the tunneling coupling strength with the leads and the discrete energy levels, can be controlled by the planar magnetization and the sample size. Specially, different from the conventional QD, we find that the angle between two planar magnetization orientations provides an effective way to manipulate the discrete energy levels. Combining the numerical calculation and the theoretical analysis, we identify that such manipulation originates from the unique quantum confinement effect of the topological edge states. Based on such mechanism, we find the spin transport properties of QDs can also be controlled.

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“…Notably, a viable material in this connection must be a ferromagnetic insulating material with a topologically non-trivial electronic band structure. 3,17,25,26 A number of 2D materials, mainly in the honeycomb structure with different functionalizations, of elements of groups IV 27,28 , V, [29][30][31] and III-V [32][33][34][35][36] have been predicted to harbor the quantum-spin-Hall (QSH) phase. Recently, bimuthene has been realized on a SiC substrate with a large band gap of 0.8eV, 37 in agreement with our theoretical predictions.…”

Section: Introductionmentioning

confidence: 99%

Quantum anomalous Hall insulator phase in asymmetrically functionalized germanene

Hsu

Fang

et al. 2017

Phys. Rev. B

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Using first-principles computations, we discuss topological properties of germanene in buckled as well as planar honeycombs with asymmetric passivation via hydrogen and nitrogen (GeHN) atoms. GeHN in the planar structure is found to harbor a quantum anomalous Hall (QAH) insulator phase. Our analysis indicates that the buckled GeHN also possesses a QAH phase under tensile strain. We computed the associated Chern numbers and edge states to confirm the presence of the QAH state. In particular, chiral edge bands connecting conduction and valence bands were found at the edges of a planar zigzag GeHN nanoribbon. By considering a range of buckling distances, we demonstrate how the system undergoes the transition from the trivial to the QAH phase between the buckled and planar structures. Finally, we show CdTe(111) to be a suitable substrate for supporting buckled germanene in the QAH phase. Our results suggest that functionalized germanene could provide a robust QAH-based platform for spintronics applications.

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Edge state modulation of bilayer Bi nanoribbons by atom adsorption

Cited by 19 publications

References 30 publications

Topological phases in two-dimensional materials: a review

Topological phases in two-dimensional materials: a review

Engineering a topological quantum dot device through planar magnetization in bismuthene

Quantum anomalous Hall insulator phase in asymmetrically functionalized germanene

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