For the first time, an MIT team has managed to create three-dimensional “movies” of electron behavior in a topological insulator, or TI. The movies can capture vanishingly small increments of time — down to the level of a few femtoseconds, or millionths of a billionth of a second — so that they can catch the motions of electrons as they scatter in response to a very short pulse of light. Electrons normally have mass, just like many other fundamental particles, but when moving along the surface of TIs they move as if they were massless, like light — one of the extraordinary characteristics that give these new materials such promise for new technologies. The dramatic new results are published this week in the journal Physical Review Letters, in a paper by MIT graduate student Yihua Wang, assistant professor of physics Nuh Gedik, and six other researchers. Read the rest of the article on MIT news.
Yihua Wang makes dramatic femtosecond-resolution movie of electrons
October 8, 2012