Archive for new materials
Surprising Control over Photoelectrons from a Topological Insulator
Electrons flowing swiftly across the surface of topological insulators (TIs) are “spin polarized,” their spin and momentum locked. This new way to control electron distribution in spintronic devices makes TIs a hot topic in materials science. Now Berkeley Lab scientists have discovered more surprises: contrary to assumptions, the spin polarization of photoemitted electrons from a topological insulator is wholly determined in three dimensions by the polarization of the incident light beam.
Blocking Infinity in a Topological Insulator
In bulk, topological insulators (TIs) are good insulators, but on their surface they act as metals, with a twist: the spin and direction of electrons moving across the surface of a TI are locked together. TIs offer unique opportunities to control electric currents and magnetism, and new research by a team of scientists from China [...]
Space-Age Ceramics Get Their Toughest Test:
Space-age ceramics at their best promise advanced jet and gas turbine engines that burn with greater fuel efficiencies and less pollution. Berkeley Lab scientists have developed the first mechanical test rig for obtaining real-time X-ray computed microtomography images at ultrahigh temperatures for improving the composition and architecture of advanced ceramic composites.
Another Advance on the Road to Spintronics
Using a new technique called HARPES, for Hard x-ray Angle-Resolved PhotoEmission Spectroscopy, Berkeley Lab researchers have unlocked the ferromagnetic secrets of dilute magnetic semiconductors, materials of great interest for spintronic technology.
A New Tool to Attack the Mysteries of High-Temperature Superconductivity
Using ultrafast lasers, Berkeley Lab scientists have tackled the long-standing mystery of how Cooper pairs form in high-temperature superconductors. With pump and probe pulses spaced just trillionths of a second apart, the researchers used photoemission spectroscopy to map rapid changes in electronic states across the superconducting transition, revealing relationships of energy and momentum never seen before in these promising, but stubborn, complex materials.
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