One-dimensional helical liquids can appear at boundaries of certain condensed matter systems. Two prime examples are the edge a quantum spin Hall insulator and hinge three-dimensional second-order topological insulator. For these materials, presence state boundary serves as signature their nontrivial electronic bulk topology. Additionally, states interest themselves, novel class strongly correl...

The recent advances in the development and fabrication of semiconductor lasers have stimulated growing interest in semiconductors as candidates for optical cooling. The essential difference between semiconductors and rare-earth (RE) doped materials is in their cooling cycles. In the case of RE-doped glasses or crystals, the cooling transition occurs in localized donor ions within the host. In t...

Recent studies have reported an interesting class of semiconductor materials that bridge the gap between semiconductors and half-metallic ferromagnets. These materials, called spin gapless semiconductors, exhibit a band gap in one of the spin channels and a zero band gap in the other and thus allow for tunable spin transport. Here, we report the first experimental verification of the spin gaple...

High-technology electronic devices are based on highly specialized core materials that make their operation possible : semiconductors. Unfortunately, the range of material properties that make high-technology devices work is extremely narrow, since the sheer number of useful semiconductors is small. Hence, a major challenge has been to predict and develop new, potentially useful semiconductors....

Deposition of semiconductors and metals from chemical precursors onto planar substrates is a well-developed science and technology for microelectronics. Optical fibers are an established platform for both communications technology and fundamental research in photonics. Here, we describe a hybrid technology that integrates key aspects of both engineering disciplines, demonstrating the fabricatio...