What Is a Numerator?

A molecule is a whole composed of atoms that are combined according to a certain bonding order and spatial arrangement. This bonding order and spatial arrangement relationship is called molecular structure. Due to the interaction between atoms in a molecule, the physical and chemical properties of a molecule depend not only on the type and number of constituent atoms, but also on the structure of the molecule. ^[1]

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Molecular manufacturing principle

Beijing time August 29, 2014, according to foreign media reports, Yale University's science

Optical hole

Home succeeded in building the lowest temperature molecule ever. In their experiments, they lowered the temperature of selected molecules to only 2.5 K above absolute zero. This research result can be applied to a range of fields from quantum chemistry to the most basic theoretical test of particle physics, helping scientists to carry out various new research. The research paper is published in the journal Nature.

In the study, scientists at Yale University used lasers to lower the temperature of strontium monofluoride, a process known as "magneto-optical capture." Reducing the molecular temperature to near absolute zero (sub-zero) by direct cooling is a landmark achievement in the field of physics. "We can start studying the chemical reactions that occur near absolute zero," said Dr. Dave DeMiller, a professor of physics and principal researcher at Yale University. "We have the opportunity to understand the basic chemical mechanisms."

In the past, magneto-optical capture was a technology highly prized by atomic physicists, but only on a single atomic scale. The great achievement of this experiment is to set the lowest temperature ever recorded for a molecule-two or more atomic groups. This technology uses lasers to cool particles while holding them in place. Dr. DeMiller explained: "Imagine a shallow bowl filled with a little molasses. If you roll some balls into the bowl, they will sink slowly and eventually accumulate at the bottom of the bowl. Specific to our experiments, the molecules are these small Balls, molasses bowls created with laser beams and magnetic fields. " ^[2]

Molecular inspiration

The complex vibration and rotation of molecules has always been a huge challenge, and magneto-optical capture cannot be performed.

Magneto-optical capture technology uses lasers to hold molecules in place

Yale's research team took a unique approach to capture, inspired by an obscure research paper from the 1990s. This paper describes magneto-optical capture-type results produced under conditions where cooling and capture requirements are often not met.

DeMiller and his colleagues develop their experimental instruments in an underground laboratory. Their instruments use a lot of wiring, computers, electrical components, mirrors and cryogenic refrigerators. During the cooling process, they use more than a dozen lasers, each of which is precisely controlled. "Imagine putting an image showing high-tech into a dictionary, and we're doing something similar. Everything is very orderly, but it's still a little messy," De Miller said.

Yale's research team chose strontium monofluoride because their structure is simple-an electron moves around the entire molecule. "We used to think that the ideal choice was diatomic molecules," DeMiller pointed out. This research has opened a door that can be applied to a range of fields-from precise measurement and quantum simulation to ultra-cool chemistry to particles Testing of Standard Models of Physics-Let scientists conduct further experiments. " ^[2]