A small amount of compressive strain turns a nonmetallic form of tin into a 3D topological Dirac semimetal—a kind of “supermetal” with very high electron mobility. With its rich topological phase diagram, the material shows promise for both novel physics and eventual device applications. Read more »
Altered States in Graphene Heterostructures
ARPES directly reveals for the first time how electronic states are altered when epitaxial graphene is deposited on a substrate of hexagonal boron nitride (h-BN). The interaction between the materials in this heterostructure greatly improves its suitability for advanced, ultralow-power device applications. Read more »
A New Universal Parameter for Superconductivity
Scientists have been researching high-temperature (high-Tc) superconductors for decades with the goal of finding materials that express superconducting capabilities at room temperature, which would be a requirement for practical and cost-effective applications. The newest materials to gain scientific interest are iron-based superconductors, and the latest research from the ALS on these materials indicates a new factor that determines their superconductivity. Read more »
Weyl Fermions Discovered After 85 Years
Weyl fermions, elusive massless particles first theorized 85 years ago, have now been detected as emergent quasiparticles in synthetic crystals of the semimetal TaAs. The discovery could allow for the nearly free and efficient flow of electricity, as well as the realization of many fascinating topological quantum phenomena.
Discovery of Weyl Semimetals May Lead to Novel Future Spintronic Applications
A team of researchers using angle-resolved photoemission spectroscopy (ARPES) at ALS Beamline 10.0.1 found intriguing particles in a new phase of quantum matter: topological Weyl semimetals.
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Graphene’s 3D Counterpart
ALS researchers have discovered a material that is essentially a 3D version of graphene — the 2D sheets of carbon through which electrons race at many times the speed at which they move through silicon. The discovery promises exciting new things to come for the high-tech industry, including much faster transistors and far more compact hard drives. Read more »
Minding the Gap Makes for More Efficient Solar Cells
Using novel materials to develop thin, flexible, and more efficient photovoltaic cells is one of the hottest topics in current materials research. A class of transition metals undergoes a dramatic change that makes them ideal for solar energy applications. Read more »
ALS Reveals New State of Matter
ALS user groups from Princeton and Stanford have been making waves this past year with several high-profile papers and extensive news coverage of their work on a new state of matter embodied by so-called “topological insulators,” materials that conduct electricity only on their surfaces. Read more »