Topological Insulators: Bismuth is Better than Previously Thought
High performance computing, quantum computing, and other quantum technologies are advanced when research, such as that reported by MIT, finds practical applications. Superconductors, superconductivity, superconducting materials are seen as a conduit to advancing the world into the 4th Industrial Revolution Because quantum is coming. Qubit.
New insights into bismuth’s character
Points to note…
+ While materials scientists seek to identify materials with fast electrical conduction and low heat output for advanced computers, physicists want to classify the types of topological and other properties that underlie these better-performing materials.
If electrons flowing through copper are like a school of fish swimming through a lake in summer, electrons flowing across a topological surface are more like ice skaters crossing the lake’s frozen surface in winter. For bismuth, however, in the hinge state, their motion would be more akin to skating on the corner edge of an ice cube.
+ Bismuth also features a topological state along certain edges of the crystal where two vertical and horizontal faces meet, called a “hinge” state. To fully realize the desired topological effects in this material, the hinge state and other surface states must be coupled to another electronic phenomenon known as “band inversion” that the theorists’ calculations show also is present in bismuth. They predict that these topological surface states could be confirmed by using an experimental technique known as photoemission spectroscopy.
+ The researchers also found that in the hinge state, as the electrons move forward, their momentum and another property, called spin — which defines a clockwise or counterclockwise rotation of the electrons — is “locked.” “Their direction of spinning is locked with respect to their direction of motion,” Xu explains. These additional topological states might help explain why bismuth lets electrons travel through it much farther than most other materials, and why it conducts electricity efficiently with many fewer electrons than materials such as copper.
Content may have been edited for style and clarity.