Scientists from Israel have presented a new technique that allows you to fix sound and light waves in the finest materials.
Using an ultrafast transmission electron microscope, researchers at the Technion Israel Institute of Technology have recorded the propagation of combined sound and light waves in atomically thin materials for the first time.
The experiments were carried out in the laboratory of electron beam quantum dynamics. Single-layer materials, also known as two-dimensional materials, are new in themselves, consisting of a single layer of atoms. Now, scientists at the Technion have shown for the first time how pulses of light travel within these materials. Their results appeared in the journal Science.
Light moves through space at a speed of 300 thousand km / s. Passing through water or glass, it slows down for a fraction of a second. But when passing through some solid bodies with several layers, light slows down almost a thousand times. This is because light causes the atoms of these special materials to vibrate, creating sound waves (also known as phonons), and these atomic sound waves vibrate to create light.
Scientists shone in pulses along the edge of the two-dimensional material, creating hybrid sound-light waves in it. Not only were they able to record these waves, but they found that the impulses can spontaneously accelerate and decelerate. These waves even split into two separate impulses moving at different speeds.
“Unlike other methods, our new technique allows us to capture the movement of light without disturbing it. Our results could not be achieved with existing methods. Thus, in addition to our scientific findings, we present a previously unseen measurement technique that will have implications for many other scientific discoveries, ”the researchers added.