Topological Insulators Found More Fragile Than Thought
Researchers Explain the Strange Electron Flow in Future Materials
Excerpts and salient points ~
+ Electrons race along the surface of certain unusual crystalline materials, except that sometimes they don’t. Two new studies from Princeton researchers and their collaborators explain the source of the surprising behavior and chart a course for restoring conductivity in these remarkable crystals, prized for their potential use in future technologies including quantum computers.
Researchers demonstrate how the perfect flow of electrons on the surface of some types of topological insulators can be surprisingly fragile.
+ [A] class of materials known as topological insulators has dominated the search for the materials of the future. These crystals have an uncommon property: Their interiors are insulators — where electrons cannot flow — but their surfaces are perfect conductors, where electrons flow without resistance.
+ That was the picture until the discovery two years ago that some topological materials are actually unable to conduct current on their surface, a phenomenon that earned the name “fragile topology.”
+ “This was a very left-field idea and realization,” Huber said. “We can now show that virtually all topological states that have been realized in our artificial systems are fragile, and not stable as was thought in the past. This work provides that confirmation, but much more, it introduces a new overarching principle.”
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