Phase transitions occur when a substance changes from a solid, liquid or gaseous state to a different state -- like ice melting or vapor condensing. During these phase transitions, there is a point at which the system can display properties of both states of matter simultaneously. A similar effect occurs when normal metals transition into superconductors -- characteristics fluctuate and properties expected to belong to one state carry into the other.
Scientists at Harvard have developed a bismuth-based, two-dimensional superconductor that is only one nanometer thick. By studying fluctuations in this ultra-thin material as it transitions into superconductivity, the scientists gained insight into the processes that drive superconductivity more generally. Because they can carry electric currents with near-zero resistance, as they are improved, superconducting materials will have applications in virtually any technology that uses electricity.
The Harvard scientists used the new technology to experimentally confirm a 23-year-old theory of superconductors developed by scientist Valerii Vinokur from the U.S. Department of Energy's (DOE) Argonne National Laboratory.
"Sometimes you discover something new and exotic, but sometimes you just confirm that you do, after all, understand the behavior of the every-day thing that is right in front of you." -- Valerii Vinokur, Argonne Distinguished Fellow, Materials Science division.To read more, click here.