相关论文: Topological insulators for high performance terahe…
We have identified epitaxially grown elemental Te as a capping material that is suited to protect the topological surface states of intrinsically insulating Bi$_2$Te$_3$. By using angle-resolved photoemission, we were able to show that the…
An electron moving in a magnetically ordered background feels an effective magnetic field that can be both stronger and more rapidly varying than typical externally applied fields. One consequence is that insulating magnetic materials in…
In this paper, by first principle calculations, we investigate systematically the band topology of a new half-Heusler family with composition of I(A)-III(A)-IV(A). The results clearly show that many of the I-III-IV half-Heusler compounds…
The tunability of the chemical potential for a wide range encompassing the Dirac point is important for many future devices based on topological insulators. Here we report a method to fabricate highly efficient top gates on epitaxially…
Topologically protected surface states of three-dimensional topological insulators provide a model framework for studying massless Dirac electrons in two dimensions. Usually a step on the surface of a topological insulator is treated as a…
We discuss possible topological phase transitions in Ge-based thin films of Ge(Bi$_x$Sb$_{1-x}$)$_2$Te$_4$ as a function of layer thickness and Bi concentration $x$ using the first principles density functional theory framework. The bulk…
By numerically solving the effective continuous model of a topological insulator with parameters corresponding to the band structure of the topological insulator Bi2Se3 , we analyze possible appearance of one-dimensional states in various…
Recently, higher-order topological insulators have been attracting extensive interest. Unlike the conventional topological insulators that demand bulk gap closings at transition points, the higher-order band topology can be changed without…
Chemical bond analysis for the topological insulator (TI) Bi2Se3 following valence bond theory and VSEPR rule is proposed and compared to that of graphene. The existence of pi-bond trimers on surface Se-layer is revealed to be responsible…
Twisting the stacking of layered materials leads to rich new physics. A three dimensional (3D) topological insulator film host two dimensional gapless Dirac electrons on top and bottom surfaces, which, when the film is below some critical…
We have designed three-dimensional models of topological insulator thin films, showing a tunability of the odd number of Dirac cones on opposite surfaces driven by the atomic-scale geometry at the boundaries. This enables creation of a…
The newly-discovered three-dimensional strong topological insulators (STIs) exhibit topologically-protected Dirac surface states. While the STI surface state has been studied spectroscopically by e.g. photoemission and scanned probes,…
Two-dimensional (2D) topological insulators (TIs), a new state of quantum matter, are promising for achieving the low-power-consuming electronic devices owning to the remarkable robustness of their conducting edge states against…
The discovery of two-dimensional topological photonic systems has transformed our views on electromagnetic propagation and scattering of classical waves, and a quest for similar states in three dimensions, known to exist in condensed matter…
We measure gate-tuned thermoelectric power of mechanically exfoliated Bi2Se3 thin films in the topological insulator regime. The sign of the thermoelectric power changes across the charge neutrality point as the majority carrier type…
Ultrafast carrier dynamics in the topological insulator Bi2Se3 have recently been intensively studied using a variety of techniques. However, we are not aware of any successful experiments exploiting transient absorption (TA) spectroscopy…
Although the richness of spatial symmetries has led to a rapidly expanding inventory of possible topological crystalline (TC) phases of electrons, physical realizations have been slow to materialize due to the practical difficulty to…
Topological insulators represent a paradigm shift in surface physics. The most extensively studied Bi$_2$Se$_3$-type topological insulators exhibit layered structures, wherein neighboring layers are weakly bonded by van der Waals…
The concept of topological insulator (TI) has introduced a new point of view to condensed-matter physics, relating a priori unrelated subfields such as quantum (spin, anomalous) Hall effects, spin-orbit coupled materials, some classes of…
To date transport measurements of topological insulators have been dominated by the conductivity of the bulk, leading to substantial difficulties in resolving the properties of the surface. To this end, we use high magnetic field, rf- and…