40 research outputs found
ZnSe nanotrenches: formation mechanism and its role as a 1D template
High-resolution transmission electron microscopy was used to characterize the microstructures of ZnSe nanotrenches induced by mobile Au-alloy droplets. The contact side interfaces between the AuZnδ alloy droplets and the ZnSe as well as the four side walls of the resulting <011>-oriented nanotrenches were found all belong to the {111} plane family, with the front and back walls being the {111}A planes while the other two side walls being the {111}B planes. These findings offer a deeper understanding on the formation mechanism of the nanotrenches. Pure Au nanodashes were formed upon further deposition of Au on the nanotrenches
Impurity effect on weak anti-localization in the topological insulator Bi2Te3
We study weak anti-localization (WAL) effect in topological insulator Bi2Te3
thin films at low temperatures. Two-dimensional WAL effect associated with
surface carriers is revealed in the tilted magnetic field dependence of
magneto-conductance. Our data demonstrates that the observed WAL is robust
against deposition of non-magnetic Au impurities on the surface of the thin
films. But it is quenched by deposition of magnetic Fe impurities which destroy
the pi Berry's phase of the topological surface states. The magneto-conductance
data of a 5 nm Bi2Te3 film suggests that a crossover from symplectic to unitary
classes is observed with the deposition of Fe impurities.Comment: 4 pages, 3 figures. Corresponding author email address:
[email protected]
Tunable interaction-induced localization of surface electrons in antidot nanostructured Bi2Te3 thin films
Recently, a logarithmic decrease of conductivity has been observed in
topological insulators at low temperatures, implying a tendency of localization
of surface electrons. Here, we report quantum transport experiments on the
topological insulator Bi2Te3 thin films with arrayed antidot nanostructures.
With increasing density of the antidots, a systematic decrease is observed in
the slope of the logarithmic temperature-dependent conductivity curves,
indicating the electron-electron interaction can be tuned by the antidots.
Meanwhile, the weak anti-localization effect revealed in magnetoconductivity
exhibits an enhanced dominance of electron-electron interaction among
decoherence mechanisms. The observation can be understood from an
antidot-induced reduction of the effective dielectric constant, which controls
the interactions between the surface electrons. Our results clarify the
indispensable role of the electron-electron interaction in the localization of
surface electrons and indicate the localization of surface electrons in an
interacting topological insulator.Comment: 27 pages, article+supplemental materials, published in ACS Nan