Lasers cool or create strange states

According to the US National Geographic website, in science fiction novels, laser beams are described as powerful weapons, in real life, they are just tools used to heating and cutting. But in the latest German study, it has changed our perception of ordinary physics, with a completely new perspective that shows the properties of lasers .

In the latest study, Martin Weitz and Ulrich Vogl, two researchers at the University of Bonn in Germany took advantage of lasers, making the temperature of the rubidium gas (Rb) much lower than the normal temperature. of cold gas when switching to solid. In previous studies, scientists could only use the laser to cool the gases after being diluted.

According to Trey Porto - the physicist of the refrigeration industry, the National Institute of Standards and Technology (NIST) introduced: ' At times, when using a laser to capture some things, these things can really be done. cool, they are not only the number of atoms, but also objects that can be seen with the naked eye. '

Infrared image shows the change in temperature between the atmosphere (blue) after using cooling laser and metal around the atmosphere.After using a special laser beam to capture pulse pulse for 30 seconds, compared to the gas tank, the atmospheric temperature drops to several degrees Celsius.

According to Weitz and Vogl, they could take advantage of this process to create a new body state. Weitz said: ' For example, if you cool quickly below 0 ^° C (32 ⁰ F), this time the water will freeze, then you can predict the state of the water and the strange crystal state of the object. substance . He added, it is possible to introduce this new technology into the cooling mechanism to improve accuracy for some space observers: ' If you can cool the thermal sensor camera to observe Hang Tinh, its noise is smaller and sensitivity will be higher . '

Due to the color of the laser and the intensity associated with each other, the new technique relies heavily on red lasers. Researchers have adjusted the frequency of this laser, causing the beam to affect only the atoms that collide with each other. Next, Weitz and Vogl used this type of laser to capture the Rb gas atom of Argon gas in a high-pressure environment. Argon is an inert gas, which means it will not be easy for an atomic reaction to other elements.

But Porto explained: ' In the short time Rb atom attacked Argon atoms, Rb would attract photons from lasers. 'In addition, the effect of photonic absorption is almost the same as that of a two-atomic spring, which weakens the atomic speed when it wants to be separated. But for a moment, the extent of this ' spring ' is very large, causing the bonds of these two atoms to break, the fluorescence of the emitting atom is released.

In such a case, it takes a lot of energy to reduce the speed of photons carrying the atoms, so the process will eventually remove even more energy from the laser, used to cool Rb gas. In the experiment, the temperature of Rb in just a few seconds was from 662 ⁰ F (350 ⁰ C) to 536 ⁰ F (280 ⁰ C). The results of this study are published in the latest issue of Nature. Weitz pointed out, before putting the rapid cooling process into life, many other studies must be conducted.

But Porto said that the study and the method of dilution of air have a lot of differences, the current method of cooling air dilution has been used to study quantum effects, or prepare a gas for the meter. atom. Porto said: ' I think this research makes everyone astounded, even though you proceed to cool the object, but because it is a dense gas and a completely different mechanism. The traditional cooling capacity is very low. Meanwhile, taking advantage of lasers makes the temperature of the body decrease quickly, which really makes people surprised . "