Transport on the surface of a topological insulator

Vargiamidis, Vassilios; Vasilopoulos, P.

doi:10.1063/1.4892892

Cited by 6 publications

(9 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the coupling strength between opposite spin bands becomes weaker as λ R increases. As a result, the negative part of the conductivity due to the spin-up band diminishes and σ v yx shows the usual behaviour of gapped graphene and topological insulators [54,58]. Further, as can be seen in the inset, the band gap increases with λ R .…”

Section: Conductivitiesmentioning

confidence: 83%

See 1 more Smart Citation

Influence of interface induced valley-Zeeman and spin-orbit couplings on transport in heterostructures of graphene on WSe2

2020

Self Cite

View full text Add to dashboard Cite

We investigate the electronic dispersion and transport properties of graphene/WSe2 heterostructures in the presence of a proximity induced spin-orbit coupling (SOC) using a low-energy Hamiltonian, with different types of symmetry breaking terms, obtained from a four-band, first and second nearest-neighbour tight-binding (TB) one. The competition between different perturbation terms leads to inverted SOC bands. Further, we study the effect of symmetry breaking terms on ac and dc transport by evaluating the corresponding conductivities within linear response theory. The scattering-independent part of the valley-Hall conductivity, as a function of the Fermi energy EF , is mostly negative in the ranges −λR EF and EF λR when the strength λR of the Rashba SOC increases except for a very narrow region around EF = 0 in which it peaks sharply upward. The scattering-dependent diffusive conductivity increases linearly with electron density, is directly proportional to λR in the low-and high-density regimes, but weakens for λR = 0. We investigate the optical response in the presence of a SOC-tunable band gap for variable EF . An interesting feature of this SOC tuning is that it can be used to switch on and off the Drude-type intraband response. Furthermore, the ac conductivity exhibits interband responses due to the Rashba SOC. We also show that the valley-Hall conductivity changes sign when EF is comparable to λR and vanishes at higher values of EF . It also exhibits a strong dependence on temperature and a considerable structure as a function of the frequency.

show abstract

Section: Conductivitiesmentioning

confidence: 83%

“…, the valley-Hall conductivity is quantized in units of 2e/2h similar to the case of gapped graphene and topological insulators [54,58]. The reason is that the factor…”

Section: Conductivitiesmentioning

confidence: 96%

Influence of interface induced valley-Zeeman and spin-orbit couplings on transport in heterostructures of graphene on WSe2

2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…The form factor takes into account the topological features of the material. For a trivial twodimensional electron gas, this parameter is unity, while for topological surface states described by the Hamiltonian (10), it takes the form [100] F k; k 0…”

Section: Electron Transport (Theory)mentioning

confidence: 99%

“…The form factor takes into account the topological features of the material. For a trivial two‐dimensional electron gas, this parameter is unity, while for topological surface states described by the Hamiltonian (10), it takes the form

F true(k, {boldk}^{'} true) = \frac{1}{2} true[1 + \cos θ_{boldk k^{'}} + \frac{{normalΔ}^{2}}{ϵ_{η, boldk}^{2}} true(1 - \cos θ_{k {boldk}^{'}} true) true] .

The dielectric function can be represented in the form ϵ ( q ) = 1 + q s / q , where q s is the inverse screening length . In the general case, q s depends on q .…”

Section: Electron Transport (Theory)mentioning

confidence: 99%

Thermoelectric Properties of Topological Insulators

Ivanov

Бурков

Pshenay-Severin

2018

Physica Status Solidi (b)

View full text Add to dashboard Cite

Many efficient thermoelectric materials belong to the class of topological insulators. Therefore, in recent years considerable efforts have been made to elucidate the influence of nontrivial electronic topology on the thermoelectric properties of thermoelectrics. This review describes the basic transport properties of helical surface states of topological insulators. Their effect on the thermoelectric efficiency of materials is discussed. The main attention is paid to (Bi,Sb)2(Te,Se)3 alloys, which combine the properties of the best thermoelectrics and a model topological insulator.

show abstract

“…There does however exist qualitative differences between these two types of massless Dirac Fermions, chief among them is that the quantum spin Hall effect only exists in the surface states of TI's. Due to the linear dispersion relation around the Dirac point there has been a considerable amount of interest in the optical properties of the aforementioned two-dimensional systems 8 . It is yet to be seen however, what effect there is on the optical properties of a system whereby a coupling occurs between these two similar two-dimensional systems.…”

mentioning

confidence: 99%

Optical conductivity of a commensurate graphene-topological insulator heterostructure

Sanderson¹,

Huang²,

Bao³

et al. 2017

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

The optical conductivity of a heterostructure formed by a commensurate stacking of graphene and a topological insulator (TI) is investigated using the Kubo formalism. Both the intra-and interband AC conductivities are found to be sensitive to the graphene-TI coupling. The direct interband transition in graphene which is the origin of the universal conductance is forbidden due to the topological nature is the coupling. Furthermore, the graphene-TI coupling gives rise to additional broken symmetries, resulting in both the inter-and intraband conductivity to be reduced in the graphene-TI heterostructure. By varying the Fermi energy of the heterostructure, the band that gives the largest contribution changes, which in turn affects the overall electronic transport.

show abstract

Transport on the surface of a topological insulator

Cited by 6 publications

References 30 publications

Influence of interface induced valley-Zeeman and spin-orbit couplings on transport in heterostructures of graphene on WSe2

Influence of interface induced valley-Zeeman and spin-orbit couplings on transport in heterostructures of graphene on WSe2

Thermoelectric Properties of Topological Insulators

Optical conductivity of a commensurate graphene-topological insulator heterostructure

Contact Info

Product

Resources

About