2021-05-08

Researchers used ultra-high-speed laser experiments to find that bubbles formed around atoms can accelerate energy transfer

By yqqlm yqqlm

Researchers used ultra-high-speed laser experiments to find that bubbles formed around atoms can accelerate energy transfer

Imagine that the same exchange happens in a busy room , Other people bumping into you usually make the delivery complicated and slow. Then, imagine how much faster the communication would be if everyone took a step back and created a safe bubble to allow communication to proceed unhindered.

An international scientific team led by University of Connecticut physics professor Nora Berrah and postdoctoral researcher and lead author Aaron LaForge (Aaron LaForge) witnessed the use of ultrafast lasers This bubble-mediated enhancement between two helium atoms. Their results are now published in “Physical Review X”.

LaForge said that measuring the energy exchange between atoms requires fast measurements that are almost unimaginable. LaForge said: “The reason for the need for a shorter time scale is that when you look at microscopic systems, such as atoms or molecules, their motion is very fast, on the order of femtoseconds (10-15 seconds). This is because they move. A few angstroms (10-10 meters) time”.

LaForge explained that these measurements are made by so-called free electron lasers, in which electrons are accelerated to close to the speed of light, and then using several sets of magnets, the electrons are forced to fluctuate, which causes them to emit short-wavelength light. . LaForge said: “With ultra-fast laser pulses, you can time-analyze a process to figure out how fast or slow something happens.”

The first step in the experiment is to initiate this process, LaForge said: “Physicists probe and perturb a system in order to measure its response by taking a quick snapshot of the response. So, essentially, we The purpose of is to make a dynamic molecular movie. In this case, we first initiated the formation of two bubbles in a helium nanodrop. Then, using the second pulse, we determined that they could interact speed”.

Through the second laser pulse, the researchers measured the interaction of the bubbles: after exciting the two atoms, two bubbles were formed around the atoms. Then, the atoms can move and interact without having to push the surrounding atoms or molecules.

Helium nanodrops are used as a model system because helium is one of the simplest atoms in the periodic table, LaForge explained that this is an important consideration. Although there are about one million helium atoms in a nanodroplet, its electronic structure is relatively simple, and there are fewer elements to consider in the system, and the interaction is easier to clarify.