Current propagation behaviors and spin filtering effects in three-terminal topological-insulator junctions

Yang, Jia-En; Lü, Xiao-Long; Xie, Hang

doi:10.1088/1367-2630/abbbd2

Cited by 10 publications

(4 citation statements)

References 21 publications

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“…Electric field driven topological phase switching between a topological and a trivial phase can be harnessed in the form of topological field effect transistors (TFETs) [1][2][3]. The pursuit of such a transition in two-dimensional (2D) materials has seen significant activity [4][5][6][7][8][9][10][11][12][13][14] and experimental progress [3,15,16] recently. In 2D-Xene materials, where 'X' refers to Si, Ge, Sb, etc a perpendicular electric field can trigger a 1 Current address: Electrical Engineering and Computer Sciences, University of California, Berkeley, CA 94720, United States of America.…”

Section: Introductionmentioning

confidence: 99%

Momentum relaxation effects in 2D-Xene field effect device structures

Basak¹,

Brahma²,

Muralidharan³

2021

J. Phys. D: Appl. Phys.

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We analyze the electric field driven topological field effect transition on 2D-xene materials with the addition of momentum relaxation effects, in order to account for dephasing processes. The topological field effect transition between the quantum spin Hall phase and the quantum valley Hall phase is analyzed in detail using the Keldysh non-equilibrium Green’s function technique with the inclusion of momentum and phase relaxation, within the self-consistent Born approximation. Details of the transition with applied electric field are elucidated for the ON–OFF characteristics with emphasis on the transport properties along with the tomography of the current carrying edge states. We note that for moderate momentum relaxation, the current carrying quantum spin Hall edge states are still pristine and show moderate decay with propagation. To facilitate our analysis, we introduce two metrics in our calculations, the coherent transmission and the effective transmission. In elucidating the physics clearly, we show that the effective transmission, which is derived rigorously from the quantum mechanical current operator is indeed the right quantity to analyze topological stability against dephasing. Exploring further, we show that the insulating quantum valley Hall phase, as a result of dephasing carries band-tails which potentially activates parasitic OFF currents, thereby degrading the ON–OFF ratios. Our analysis sets the stage for realistic modeling of topological field effect devices for various applications, with the inclusion of scattering effects and analyzing their role in the optimization of the device performance.

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Section: Introductionmentioning

confidence: 99%

Momentum relaxation effects in 2D-Xene field effect device structures

Basak¹,

Brahma²,

Muralidharan³

2021

J. Phys. D: Appl. Phys.

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“…Afterward, Kane and Mele [7,8] predicted the quantum spin Hall (QSH) effect in graphene, which is characterized by helical edge states. Due to the importance of designing lowdissipation electronic devices [9][10][11][12][13][14][15], researchers are committed to nding more topological edge states.…”

Section: Introductionmentioning

confidence: 99%

Modulation of antichiral edge states in zigzag graphene nanoribbons by side potential

Yang¹,

Lü

Xie³

2022

Preprint

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Antichiral edge states induced by the modified Haldane model have been predicted by Colomés and Franz (Physical Review Letters, 2018, 120(8): 086603). By applying the side potential composed of a potential field, staggered electric field, and exchange field along the boundaries of zigzag graphene nanoribbons (zGNRs), we further propose other types of antichiral edge states and investigate their corresponding transport properties. It is found that the side potential could destroy one or two (spin) edge modes, eventually inducing five novel antichiral edge states. By calculating the effect of these external fields separately on the energy band of the zGNRs, the regulatory mechanism has been explained. In addition, based on these induced edge states, we also proposed the spin/charge switcher in the three-terminal device consisting of zGNRs. We believe that these results could be used for the future designs of spintronic devices.

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“…Electric field driven topological phase switching between a topological and a trivial phase can be harnessed in the form of topological field effect transistors (TFET) [1][2][3]. The pursuit of such a transition in two-dimensional (2D) materials has seen significant activity [4][5][6][7][8][9][10][11][12][13][14] and experimental progress [3,15,16] recently. In 2D-Xene materials, where "X" refers to Si, Ge, Sb, etc., a perpendicular electric field can trigger a phase change between quantum spin Hall (QSH) phase and quantum valley Hall (QVH) phase [17].…”

Section: Introductionmentioning

confidence: 99%

Momentum relaxation effects in 2D-Xene field effect device structures

Basak,

Brahma,

Muralidharan

2021

Preprint

View full text Add to dashboard Cite

We analyze the electric field driven topological field effect transition on 2D-xene materials with the addition of momentum relaxation effects, in order to account for dephasing processes. The topological field effect transition between the quantum spin Hall phase and the quantum valley Hall phase is analyzed in detail using the Keldysh non-equilibrium Green's function technique with the inclusion of momentum and phase relaxation, within the self-consistent Born approximation. Details of the transition with applied electric field are elucidated for the ON-OFF characteristics with emphasis on the transport properties along with the tomography of the current carrying edge states. We note that for moderate momentum relaxation, the current carrying quantum spin Hall edge states are still pristine and show moderate decay with propagation. To facilitate our analysis, we introduce two metrics in our calculations, the coherent transmission and the effective transmission. In elucidating the physics clearly, we show that the effective transmission, which is derived rigorously from the quantum mechanical current operator is indeed the right quantity to analyze topological stability against dephasing. Exploring further, we show that the insulating quantum valley Hall phase, as a result of dephasing carries band-tails which potentially activates parasitic OFF currents, thereby degrading the ON-OFF ratios. Our analysis sets the stage for realistic modeling of topological field effect devices for various applications, with the inclusion of scattering effects and analyzing their role in the optimization of the device performance.

show abstract

Current propagation behaviors and spin filtering effects in three-terminal topological-insulator junctions

Cited by 10 publications

References 21 publications

Momentum relaxation effects in 2D-Xene field effect device structures

Momentum relaxation effects in 2D-Xene field effect device structures

Modulation of antichiral edge states in zigzag graphene nanoribbons by side potential

Momentum relaxation effects in 2D-Xene field effect device structures

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