Numerical guidelines for setting up a k.p simulator with applications to quantum dot heterostructures and topological insulators

Sengupta, Parijat; Ryu, Hoon; Lee, Sunhee; Tan, Yaohua; Klimeck, Gerhard

doi:10.1007/s10825-015-0729-6

Cited by 17 publications

(8 citation statements)

References 43 publications

(50 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…IV. The k · p surface state calculations are done by discretizing the momentum k y , and thus generating a 1D TB model with auxiliary parameters k x and k z [60]. The SDOS is then calculated using the iterative Green function method [47,48].…”

Section: Surface States From K · P Modelsmentioning

confidence: 99%

Triple Point Topological Metals

et al. 2016

View full text Add to dashboard Cite

Topologically protected fermionic quasiparticles appear in metals, where band degeneracies occur at the Fermi level, dictated by the band structure topology. While in some metals these quasiparticles are direct analogues of elementary fermionic particles of the relativistic quantum field theory, other metals can have symmetries that give rise to quasiparticles, fundamentally different from those known in high-energy physics. Here, we report on a new type of topological quasiparticles-triple point fermions-realized in metals with symmorphic crystal structure, which host crossings of three bands in the vicinity of the Fermi level protected by point group symmetries. We find two topologically different types of triple point fermions, both distinct from any other topological quasiparticles reported to date. We provide examples of existing materials that host triple point fermions of both types and discuss a variety of physical phenomena associated with these quasiparticles, such as the occurrence of topological surface Fermi arcs, transport anomalies, and topological Lifshitz transitions.

show abstract

Section: Surface States From K · P Modelsmentioning

confidence: 99%

Triple Point Topological Metals

et al. 2016

View full text Add to dashboard Cite

show abstract

“…From the bulk Hamiltonian, the corresponding representation for the quantum well is constructed on a finite-difference grid 37 by making the transformation k z = − i (∂/∂ z ) in Eq. 16 for a quantized z -axis aligned along the [111] direction.…”

Section: Methodsmentioning

confidence: 99%

Spin-dependent magneto-thermopower of narrow-gap lead chalcogenide quantum wells

Sengupta

Wen

Shi

2018

Sci Rep

Self Cite

View full text Add to dashboard Cite

A semi-classical analysis of magneto-thermopower behaviour, namely, the Seebeck and Nernst effect (NE) in quantum wells of IV-VI lead salts with significant extrinsic Rashba spin-orbit coupling (RSOC) is performed in this report. In addition to the spin-dependent Seebeck effect that has been observed before, we also theoretically predict a similar spin-delineated behavior for its magneto-thermal analog, the spin-dependent NE. The choice of lead salts follows from a two-fold advantage they offer, in part, to their superior thermoelectric properties, especially PbTe, while their low band gaps and high spin-orbit coupling make them ideal candidates to study RSOC governed effects in nanostructures. The calculations show a larger longitudinal magneto-thermopower for the spin-up electrons while the transverse components are nearly identical. In contrast, for a magnetic field free case, the related power factor calculations reveal a significantly higher contribution from the spin-down ensemble and suffer a reduction with an increase in the electron density. We also discuss qualitatively the limitations of the semi-classical approach for the extreme case of a high magnetic field and allude to the observed thermopower behaviour when the quantum Hall regime is operational. Finally, techniques to modulate the thermopower are briefly outlined.

show abstract

“…For numerical details about discretization and other steps to construct the slab Hamiltonian, the reader is referred to Ref. 36.…”

Section: Application To Smb6mentioning

confidence: 99%

Intrinsic optical conductivity of a ${{\rm{C}}}_{2v}$ symmetric topological insulator

Sengupta

Matsubara

Bellotti

et al. 2017

Semicond. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

In this work we analytically investigate the longitudinal optical conductivity of the C 2v symmetric topological insulator. The conductivity expressions at T = 0 are derived using the Kubo formula and expressed as a function of the ratio of the Dresselhaus and Rashba parameters that characterize the low-energy Hamiltonian. We find that the longitudinal inter-band conductivity vanishes when Dresselhaus and Rashba parameters are equal in strength, also called the persistent spin helix state. The calculations are extended to obtain the frequency-dependent real and imaginary components of the optical conductivity for the topological Kondo insulator SmB 6 which exhibits C 2v symmetric and anisotropic Dirac cones hosting topological states at X point on the surface Brillouin zone. arXiv:1509.08984v6 [cond-mat.mes-hall]

show abstract

Numerical guidelines for setting up a k.p simulator with applications to quantum dot heterostructures and topological insulators

Cited by 17 publications

References 43 publications

Triple Point Topological Metals

Triple Point Topological Metals

Spin-dependent magneto-thermopower of narrow-gap lead chalcogenide quantum wells

Intrinsic optical conductivity of a ${{\rm{C}}}_{2v}$ symmetric topological insulator

Contact Info

Product

Resources

About