Efficiency of electrical manipulation in two-dimensional topological insulators

Pang, Maolin; Wu, Xiaoguang

doi:10.1088/1674-1056/23/7/077302

Cited by 3 publications

(2 citation statements)

References 40 publications

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“…We can see that the Kondo resonance for each spin is clearly observed by a sharp peak around Fermi energy, which is caused by the Kondo effect in DOS. [13] From Fig. 3(a), when θ = π, namely, the magnetic moments of the two FM leads are antiparallel (AP), the behaviors of the DOS for up and down spins in leads is similar, which also has one sharp peak at the Fermi energy.…”

Section: Resultsmentioning

confidence: 99%

Kondo—Fano Effect in T-shaped Double Quantum Dots Coupled to Ferromagnetic Leads

Huang

Hou

2012

Commun. Theor. Phys.

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Using an equation-of-motion technique, we theoretically study the Kondo-Fano effect in the T-shaped double quantum dots coupled to two ferromagnetic leads by the Anderson Hamiltonian. We calculate the density of states in this system by solving Green function. Our results reveal that the density of states show some noticeable characteristics not only depending upon the interdot coupling t ab , the energy level ε d1 of the side coupled quantum dot QD b , and the relative angle θ of magnetic moment M, but also the asymmetry parameter α in ferromagnetic leads and so on. All these parameters greatly influence the density of states of the central quantum dot QDa. This system is a possible candidate for spin valve transistors and may have potential applications in the spintronics.

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Section: Resultsmentioning

confidence: 99%

Kondo—Fano Effect in T-shaped Double Quantum Dots Coupled to Ferromagnetic Leads

Huang

Hou

2012

Commun. Theor. Phys.

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“…Recently, many groups have devoted considerable efforts to the theoretical and experimental study of the QSH state in the HgTe QW, inspired by the potential applications of the QSH effect for spintronic devices. [12][13][14][15][16][17][18][19][20][21][22][23][24][25] When the thickness d of the HgTe/CdTe QW is varied through a critical thickness d c (= 6.3 nm), the transition of electronic band structure from a normal to an "inverted" type occurs, i.e., the case of d < d c corresponding to the NI and the case of d > d c to the TI. [10] According to the BHZ model, the mass or gap parameter M of the model changes its sign when the above-mentioned topological quantum phase transition from the normal to the topological insulating phase takes place.…”

Section: Introductionmentioning

confidence: 99%

Finite size effects on the quantum spin Hall state in HgTe quantum wells under two different types of boundary conditions

Zhi¹,

Chen²,

Zhou³

2015

Chinese Phys. B

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The finite size effect in a two-dimensional topological insulator can induce an energy gap Eg in the spectrum of helical edge states for a strip of finite width. In a recent work, it has been found that when the spin–orbit coupling due to bulk-inversion asymmetry is taken into account, the energy gap Eg of the edge states features an oscillating exponential decay as a function of the strip width of the inverted HgTe quantum well. In this paper, we investigate the effects of the interface between a topological insulator and a normal insulator on the finite size effect in the HgTe quantum well by means of the numerical diagonalization method. Two different types of boundary conditions, i.e., the symmetric and asymmetric geometries, are considered. It is found that due to the existence of the interface between topological insulator and normal insulator this oscillatory pattern on the exponential decay induced by bulk-inversion asymmetry is modulated by the width of normal insulator regions. With the variation of the width of normal insulator regions, the shift of the Dirac point of the edge states in the spectrum and the energy gap Eg closing point in the oscillatory pattern can occur. Additionally, the effect of the spin–orbit coupling due to structure-inversion asymmetry on the finite size effects is also investigated.

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Coexistence and decoupling of bulk and edge states in disordered two-dimensional topological insulators

Zhang

Man

et al. 2014

Phys. Rev. B

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We investigate the scattering and localization properties of edge and bulk states in a disordered twodimensional topological insulator when they coexist at the same fermi energy. Due to edge-bulk backscattering (which is not prohibited a priori by topology or symmetry), Anderson disorder makes the edge and bulk states localized indistinguishably. Two methods are proposed to effectively decouple them and to restore robust transport. The first kind of decouple is from long range disorder, since edge and bulk states are well separated in k space. The second one is from an edge gating, owing to the edge nature of edge states in real space. The latter can be used to electrically tune a system between an Anderson insulator and a topologically robust conductor, i.e., a realization of a topological transistor.

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Efficiency of electrical manipulation in two-dimensional topological insulators

Cited by 3 publications

References 40 publications

Kondo—Fano Effect in T-shaped Double Quantum Dots Coupled to Ferromagnetic Leads

Kondo—Fano Effect in T-shaped Double Quantum Dots Coupled to Ferromagnetic Leads

Finite size effects on the quantum spin Hall state in HgTe quantum wells under two different types of boundary conditions

Coexistence and decoupling of bulk and edge states in disordered two-dimensional topological insulators

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