| Title | Ultrafast Slow-Motion Microscope Sees a Single Molecule Vibrate | |
| Date | Sunday November 13 2016, @09:35PM | |
| Author | martyb | |
| Topic | ||
| from the whither-Heisenberg? dept. | ||
even though the question of how individual atoms and molecules behave is at the heart of all fields of natural science, until recently, nobody had ever seen a single molecule move on its intrinsic ultrafast timescale. In order to literally watch their motion, one would need a microscope many billions of times more rapid than the fastest high-speed cameras, which has until now remained way out of reach.
An international team of scientists based in Regensburg, Germany, has now tackled this challenge. Their aim was to revolutionize the way in which researchers look at the nanoworld: advancing from images to moving images of molecules. To do so, they developed an unprecedented ultrafast microscope. They combined the most powerful tool researchers have to access ultrafast time scales, femtosecond laser pulses, with highly advanced scanning tunneling microscopy capable of imaging individual molecules. The principle of this microscopy technique is similar to a record player.
A sharp needle is moved across a surface to reveal its relief. But in scanning tunneling microscopy, the tip of this needle is as sharp as a single atom. Also, it does not touch the surface, but hovers over it while electrons move between the tip and surface thanks to a quantum mechanical effect called tunneling. As a result, the tip serves as a probe that is sensitive to corrugation smaller than a single molecule.
The researchers in Regensburg developed a novel scheme by controlling the tunneling process by ultrafast light pulses so short that each pulse only contained one single oscillation cycle of the lightwave. This mechanism gives them total quantum control over a select electron within a single molecule with simultaneous femtosecond temporal and sub-ångström spatial precision. As a result, they realized a microscope that not only allows them to image individual molecules, but also to "see" them move on their intrinsic time scale.
| Links |
printed from SoylentNews, Ultrafast Slow-Motion Microscope Sees a Single Molecule Vibrate on 2025-12-14 04:41:32