MIT researchers have emerged from their smoke filled labs after watching a coupling of photons and electrons on a topological insulator.
This type of coupling had been predicted by theorists, but never observed, mostly because the photons and electrons are rather shy.
The researchers think that now they have seen photons and electrons entwined on a topological insulator they can move on to create materials whose electronic properties could be “tuned” in real time simply by shining precise laser beams.
According to this week’s copy of Science, which we get for the coupling centrefold, the work “opens up a new avenue for optical manipulation of quantum states of matter”.
Nuh Gedik and Sarah Biedenharn, associate professor of physics and senior author of a paper ,described shooting femtosecond pulses of mid-infrared light at a sample of material. They then look at an electron spectrometer.
They have seen a quantum-mechanical mixture of electrons and photons, known as a Floquet-Bloch state, in a crystalline solid.
Swiss physicist Felix Bloch theorised this and thought it was because electrons move in a crystal in a regular, repeating pattern dictated by the periodic structure of the crystal lattice.
Victor Galitski, a professor of physics at the University of Maryland who was not involved in this research, it “opens new avenues not only for optical control of topological states, but also more generally for engineering of new kinds of electronic states in solid-state systems”.
It all suggested that it was possible to alter the electronic properties of a material from a conductor to a semiconductor just by changing the laser beam’s polarisation.
It could mean that you could make a chip, which does not heat up at all. You could make a material to conduct electricity, or to be transparent simply shining light on the materials.