Chemistry takes effort. Whether by raising the temperature, increasing the odds of matching atoms colliding in a hot collision, or increasing the pressure and squeezing them together, building molecules usually requires a certain cost in energy.
Quantum theory provides a solution if you are patient. A team of researchers from the University of Innsbruck in Austria has finally seen quantum tunneling in action in the world’s first experiment measuring the fusion of deuterium ions with hydrogen molecules.
A tunnel is a strangeness in the quantum universe that makes it seem as if particles can pass through obstacles that would normally be difficult to overcome.
In chemistry, this obstacle is the energy required for atoms to communicate with each other, or with existing molecules.
However, the theory goes that in extremely rare cases, it is possible for atoms near to ‘tunnel’ their way through this energy barrier and connect without any effort.
“Quantum mechanics allows particles to break through the energy barrier due to their quantum mechanical wave properties, and interaction takes place,” He says First author Robert Wilde, an experimental physicist from the University of Innsbruck.
Quantum waves are the ghosts that drive the behavior of things like electrons, photons, and even entire groups of atoms, blurring their existence before any observation, so they don’t sit in any specific place but occupy a continuum of possible positions.
This dimming is not significant for larger objects such as particles, cats, and galaxies. But as we zoom in on individual subatomic particles, the range of possibilities widens, forcing the site states of the various quantum waves to overlap.
When that happens, the particles have little chance of popping up where they have no work, or tunneling into areas that would require a great deal of force to enter.
One of those areas of an electron might be within the bonding region of a chemical reaction, where it welds neighboring atoms and molecules together without breaking through heat or pressure.
Understanding the role quantum tunneling plays in building and rearranging molecules could have important implications for calculations of energy release in nuclear reactions, such as those involving hydrogen in stars and fusion reactors here on Earth.
while We have modeled this phenomenon For examples involving reactions between a negatively charged form of deuterium – an isotope of hydrogen that contains a neutron – and dihydrogen, or H2Proving the numbers experimentally requires a difficult level of precision.
To accomplish this, Wilde and his colleagues cooled the negative deuterium ions to a temperature that brought them near to a standstill before introducing a gas made of hydrogen molecules.
Without heat, the probability of a deuterium ion obtaining the energy needed to force hydrogen molecules to rearrange atoms was much lower. However, it also forced the particles to sit quietly closer together, giving them more time to bond through the tunnels.
“In our experiment, we give the potential reactions in the trap about 15 minutes and then determine the amount of hydrogen ions formed. From their number, we can deduce how often the reaction will occur,” Wilde explains.
This number is just over 5 x 10-20 Reactions per second that occur per cubic centimeter, or about one tunneling event per hundred billion collisions. So not much. Although the experience supports previous modeling, confirming a criterion that can be used in predictions elsewhere.
Since tunnels play a rather important role in a variety of nuclear and chemical reactions, many of which are also likely to occur in the cold depths of space, getting a fine grip on the factors at play gives us a more solid foundation to rule. Our expectations are on.
This research has been published in nature.
“Infuriatingly humble alcohol fanatic. Unapologetic beer practitioner. Analyst.”