Quantum-confined Stark effect in band-inverted junctions

Díaz‐Fernández, Álvaro; Domı́nguez-Adame, F.

doi:10.1016/j.physe.2017.06.026

Cited by 9 publications

(19 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, we have observed that the reduction in the velocity squares with the applied field, a feature that was recently found also in the case of static fields. 10,11 Our study provides a more promising experimental set up in order to obtain an anisotropic renormalization of the velocity based on a time-periodic driving and no need for a magnetic field. 13 All of our findings should be straightforwardly probed by means of time-and angle-resolved photoemission spectroscopy, as discussed in Ref.…”

Section: Discussionmentioning

confidence: 99%

Floquet engineering of Dirac cones on the surface of a topological insulator

et al. 2019

Self Cite

View full text Add to dashboard Cite

We propose to Floquet-engineer Dirac cones at the surface of a three-dimensional topological insulator. We show that a large tunability of the Fermi velocity can be achieved as a function of the polarization, direction and amplitude of the driving field. Using this external control, the Dirac cones in the quasienergy spectrum may become elliptic or massive, in accordance to experimental evidences. These results help us to understand the interplay of surface states and external ac driving fields in topological insulators. In our work we use the full Hamiltonian for the three-dimensional system instead of effective surface Hamiltonians, which are usually considered in the literature. Our findings show that the Dirac cones in the quasienergy spectrum remain robust even in the presence of bulk states and, therefore, they validate the usage of effective surface Hamiltonians to explore the properties of Floquet-driven topological boundaries. Furthermore, our model allows us to introduce new out-of-plane field configurations, which cannot be accounted for by effective surface Hamiltonians.

show abstract

Section: Discussionmentioning

confidence: 99%

Floquet engineering of Dirac cones on the surface of a topological insulator

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…Earlier works in Dirac materials have proven that a renormalization of the Fermi velocity of the surface states occurs in the presence of a perpendicular electric field. 34,35 Therefore, we expect similar effects in WSMs and DSMs. We approach the problem in two ways: i) by way of perturbation theory (PT) to obtain analytic results and ii) by performing numerical calculations based on the Python package Kwant.…”

Section: Electric Fieldmentioning

confidence: 78%

Electric field manipulation of surface states in topological semimetals

et al. 2019

View full text Add to dashboard Cite

We investigate the consequences of applying electric fields perpendicularly to thin films of topological semimetals. In particular, we consider Weyl and Dirac semimetals in a configuration such that their surface Fermi arcs lie on opposite edges of the films. We develop an analytical approach based on perturbation theory and a single-surface approximation and we compare our analytical results with numerical calculations. The effect of the electric field on the dispersion is twofold: it shifts the dispersion relation and renormalizes the Fermi velocity, which would, in turn, have direct effects on quantum transport measurements. Additionally, it modifies the spatial decay properties of surface states which will impact the connection of the Fermi arcs in opposite sides of a narrow thin film.

show abstract

“…All these topological states of matter were already encountered in a series of seminal papers by Volkov and Pankratov in the 1980s [80][81][82][83][84][85]. Remarkably, these states can be reshaped by means of external electric and magnetic fields [86][87][88][89] and doping [90,91]. Another example of these such states can be found in HgTe.…”

Section: Topological Insulator Nanowiresmentioning

confidence: 99%

Nanowires: A route to efficient thermoelectric devices

Domı́nguez-Adame

Martín‐González

Sánchez

et al. 2019

Physica E: Low-dimensional Systems and Nanostructures

View full text Add to dashboard Cite

Miniaturization of electronic devices aims at manufacturing ever smaller products, from mesoscopic to nanoscopic sizes. This trend is challenging because the increased levels of dissipated power demands a better understanding of heat transport in small volumes. A significant amount of the consumed energy in electronics is transformed into heat and dissipated to the environment. Thermoelectric materials offer the possibility to harness dissipated energy and make devices less energy-demanding. Heat-to-electricity conversion requires materials with a strongly suppressed thermal conductivity but still high electronic conduction. Nanowires can meet nicely these two requirements because enhanced phonon scattering at the surface and defects reduces the lattice thermal conductivity while electric conductivity is not deteriorated, leading to an overall remarkable thermoelectric efficiency. Therefore, nanowires are regarded as a promising route to achieving valuable thermoelectric materials at the nanoscale. In this paper, we present an overview of key experimental and theoretical results concerning the thermoelectric properties of nanowires. The focus of this review is put on the physical mechanisms by which the efficiency of nanowires can be improved. Phonon scattering at surfaces and interfaces, enhancement of the power factor by quantum effects and topological protection of electron states to prevent the degradation of electrical conductivity in nanowires are thoroughly discussed.

show abstract

Quantum-confined Stark effect in band-inverted junctions

Cited by 9 publications

References 20 publications

Floquet engineering of Dirac cones on the surface of a topological insulator

Floquet engineering of Dirac cones on the surface of a topological insulator

Electric field manipulation of surface states in topological semimetals

Nanowires: A route to efficient thermoelectric devices

Contact Info

Product

Resources

About