Nanowerk May 16, 2023 The scattering of electrons at defects in 2D topological insulators is forbidden due to the unique topological protection mechanism which makes them more energy-efficient than current electronic materials. An international team of researchers (the Netherlands, Japan) made germanene was made from a single element. They melted germanium together with platinum. When the mixture cooled down, a tiny layer of germanium atoms arranged into a honeycomb lattice on top of the germanium-platinum alloy forming germanene. The conducting properties of the material could be switched ‘off’ by applying an electric field. This property is unique for a topological […]
Tag Archives: Topological insulators
Tiny lasers acting together as one: Topological vertical cavity laser arrays
Phys.org September 24, 2021 Vertical-Cavity Surface-Emitting Lasers (VCSEL) device has miniscule size of only a few microns, which sets a stringent limit on the output power it can generate. An international team of researchers (Israel, Germany) utilized the concepts of topological photonics with VCSELs that emit light vertically, while the topological process responsible for the mutual coherence and locking of the VCSELs occurs in the plane of the chip. It resulted in a powerful but very compact and efficient laser, not limited by a number of VCSEL emitters, and undisturbed by defects or altering temperatures. The topological principle of this […]
Defects may help scientists understand the exotic physics of topology
Science Daily January 22, 2021 Researchers at the University of Illinois engineered metamaterials to include defects to show that defects and structural deformations can provide insights into a real material’s hidden topological features. They experimentally demonstrated that disclination defects can robustly trap fractional charges in topological crystalline insulators (TCI) metamaterials, and the trapped charge can indicate non-trivial, higher-order crystalline topology even in the absence of any spectral signatures. They uncovered a connection between the trapped charge and the existence of topological bound states localized at these defects. By testing the robustness of these topological features when the protective crystalline symmetry […]
Novel insulators with conducting edges
Eurekalert June 1, 2018 An international team of researchers (Switzerland, Spain, USA – Princeton University, Germany, France) has predicted a new class of topological insulators, called “higher-order topological insulators”, that have conducting properties on the edges of crystals rather than on their surface. The conducting edges are extraordinarily robust. If an imperfection gets in the way of the current, it simply flows around the impurity, if the crystal breaks, the new edges automatically conduct current and in theory electricity can be conducted without any dissipation. They have proposed tin telluride as the first compound to show these novel properties. The […]