Quantum mechanics prohibits any quantum system from achieving a temperature that is equal to absolute zero. However, using Laser cooling, which is a highly efficient spectroscopic technique, atomic samples could be cooled to near absolute zero thus bringing them to their lowest achievable quantum energy state. Scientists have been advancing this technique for decades now and an important question that arose recently is whether carbon molecules, which are an integral component of life on earth, could be laser-cooled.
Understanding Laser Cooling: A Revolutionary Technique
In order to cool down any atom or molecule using a laser the first step is to understand the mechanism behind the absorption and emission of light. Knowing this is important because the same process is responsible for reducing the kinetic energy of the atom/molecule and bringing it to the lowest possible energy state (look at the figure below demonstrating the process of Laser cooling).
A team of three researchers has recently published a paper describing theoretically a new mechanism to laser cool carbon molecules [1]. The trio was able to do it by analyzing the relevant spectroscopic data from UCL’s ExoMol database which astrophysicists generally use to study exoplanetary systems. The new mechanism developed by them would supposedly allow the cooling down of the carbon molecules to temperatures close to that within the interstellar clouds and in order to study the properties of the molecules more significantly, they could also be confined using optical tweezers, which are devices that use light to manipulate microscopic objects like the atom or even bacterias.
Carbon Molecules: Bridging Physics and Chemistry
Although the research described in this article has far-reaching consequences, it is not until the actual experiments are performed and the results are vindicated that the potential applications of cooling carbon molecules would be realized significantly since the technical paper is entirely theoretical in nature. However, the research in its current stage is still very crucial with regard to the physics and chemistry of this dominant element.
As pointed out by one of the co-authors, “Carbon molecules could be the bridge between physicists’ somewhat esoteric molecules and those that chemists study with more real-life applications”.
References
[1] Niccolò Bigagli et al, Laser cooling scheme for the carbon dimer ( 12C2 ), Physical Review A (2022). DOI: 10.1103/PhysRevA.105.L051301
