The BBVA Foundation presented physicists Charles Kane and Eugene Mele the Frontiers of Knowledge Award in the Basic Sciences category for discovering materials that act as both insulators and conductors at the same time. The so-called topological insulators are a new kind of material with extraordinary electronic properties that will open new scientific avenues. They could serve to develop faster, more efficient electronic devices and even advance the advent of quantum computers.
Charles Kane and Eugene Mele’s research —both Professors and the University of Pennsylvania— led them to predict the existence of a new type of matter that did not follow the rules of physics in 2005. Until then only two type of materials were thought to exist: conductors or insulators. The seed that led to their finding was the discovery in 2004 that graphene was neither an insulator or an electric conductor. “We began to study the problem and that led us to the concept of this new insulating phase of matter,” explains Mele after the award was announced.
The physicists confirmed their prediction in experiments and postulated how to build a material that was both an insulator and conductor at the same time, or a topological insulator. In 2007, a laboratory came up with a combination of mercury and tellurium that maintained the same properties described by Kane and Mele. Ten years later, the discovery of three dimensional topological insulators in nature, such as cadmium telluride, opened the door to new lines of investigation.
Charles Kane and Eugene Mele, BBVA Foundation Frontiers of Knowledge Awards - BBVA Foundation
“We initially thought that topological insulators could only occur at energy scales too small to be directly useful, but then we discovered one could do this in three-dimensional materials at energy ranges that are routinely accessible,” notes Mele. “In fact since then we have discovered that this phenomenon is not that rare in nature, it is just that people had not thought to ask the question or look for it before.”
The discovery of topological insulators meant the discovery of new properties of matter that have always existed, but which no one had pursued. According to the award committee, the “surprising discovery” of topological insulators has confirmed “the existence of new phases of matter and ways of manipulating their properties. Moreover, the basic principles behind topological insulators have important implications beyond condensed matter physics, for instance in the generation of efficient photonic and electronic devices, or quantum information processing.”
What the future holds
The latest research on topological insulators opens up a universe of possibilities that are difficult to quantify. One of these fields is related to improving current electronic devices, which could be made even smaller. In topical insulators, “the flow of electric charge in the surface conductor is more organized than in an ordinary conductor and that might enable a smoother, more efficient flow, without overheating,” explains Kane.
Another field that will benefit from the development of these properties will be quantum computers, exponentially multiplying computing capabilities.
The most promising applications are those that do not yet exist. “The biggest pay-off may be things that we haven’t really thought of. We have a new palette of materials and when you hand that to people who are clever they will do clever things with them,” says Mele. “If I could travel ahead 50 years in a time machine, I would like to know what kinds of new devices have been developed that are informed by our basic research,” he adds.