ﻻ يوجد ملخص باللغة العربية
The transport length $l_textrm{tr}$ and the mean free path $l_textrm{e}$ are experimentally determined for bulk and surface states in a Bi$_2$Se$_3$ nanoribbon by quantum transport and transconductance measurements. We show that the anisotropic scattering of spin-helical Dirac fermions results in a strong enhancement of $l_textrm{tr}$, which confirms theoretical predictions cite{Culcer2010}. Despite strong disorder ($l_textrm{e}approx30$~nm), our result further points to the long-range nature of the scattering potential, giving a large ratio $l_textrm{tr}/l_textrm{e}approx8$ that is likely limited by a finite bulk/surface coupling. This suggests that the spin-flip length could reach the micron size in disordered 3D topological insulator nanostructures with a reduced bulk doping, even if due to charge compensation.
We report on the observation of photogalvanic effects in epitaxially grown Sb_2Te_3 three-dimensional (3D) topological insulators (TI). We show that asymmetric scattering of Dirac electrons driven back and forth by the terahertz electric field result
This study shows that a terahertz (THz) wave can be generated from the (001) surface of cleaved Bi$_{textrm{2}}$Se$_{textrm{3}}$ and Cu-doped Bi$_{textrm{2}}$Se$_{textrm{3}}$ single crystals using 800 nm femtosecond pulses. The generated THz power is
The discovery of topologically protected boundary states in topological insulators opens a new avenue toward exploring novel transport phenomena. The one-way feature of boundary states against disorders and impurities prospects great potential in app
Electron systems that possess light-like dispersion relations or the conical Dirac spectrum, such as graphene and bismuth, have recently been shown to harbor unusual collective states in high magnetic fields. Such states are possible because their li
We experimentally investigate the effect of electron temperature on transport in the two-dimensional Dirac surface states of the three-dimensional topological insulator HgTe. We find that around the minimal conductivity point, where both electrons an