Scientists recently observed a particle called the Dirac semifermion that behaves in completely unexpected ways. Depending on the direction it moves, it may appear to have mass or lack it. This phenomenon, which seems almost fantastic, could well mark the beginning of a new era in the understanding of the materials and technologies of the future.
What is a Dirac semi-fermion?
In physics, the let's say are collective entities that emerge in solid materials. Although they are not fundamental particles like electrons, they can behave similarly to real particles, but differently from individual particles. For example, in some materials, electrons can move like let's say and have amazing properties.
And semi-fermion de Dirac is a theoretical particle that was first predicted several years ago. What makes this particle so unique is its strange behavior: depending on the direction in which it moves, it can either have mass or be completely devoid of it. In other words, in a given direction, it can behave like a normal particle with a mass that limits its speed. However, in another direction, it could move as if it had no mass and propel itself at close to the speed of light, much like a photon, a particle of light.
This behavior surprised the scientific community. Dirac semi-fermions have not only theoretical interest, but also immense practical potential. They could make it possible to create materials with new properties with applications in fields as diverse as electronics, energy or even medicine.
How was the discovery related to this particle made?
The discovery of Dirac semifermions was not initially planned. In fact, the researchers weren't even looking for this specific particle when they began their experiments. The team, led by Yinming Shaoassistant professor of physics at Penn State, was studying a semi-metallic material called ZrSiSknown for its unique properties. Instead, the researchers observed something completely unexpected.
The process used to observe this particle is called magneto-optical spectroscopya very advanced method that combines the use of infrared light and powerful magnetic fields. By exposing the crystal of ZrSiS to infrared light while holding it in an intense magnetic field, the team was able to analyze how the electrons inside the material reacted to the light energy. What they observed was puzzling: the energy levels of the electrons did not follow classical patterns, but seemed to behave abnormally.
This anomaly was attributed to the presence of semi-Dirac fermions, whose properties were exactly those described in the theories of physicists several years ago. As they moved through the material, the energy levels of the electrons did not follow the expected values. Instead of moving with a constant mass like classical electrons, these let's say seemed to lose mass depending on the direction in which they moved.
To verify this phenomenon, the team had to carry out their tests in extreme conditions. The ZrSiS material was cooled to an extremely low temperature, just a few degrees above absolute zero, and immersed in an extremely powerful magnetic field (a field that is 900,000 times stronger than Earth's magnetic field). These extreme conditions were necessary to observe these quantum behaviors and confirm that Dirac semi-fermions actually existed in this material.
Why is this discovery about this particle important?
If this discovery is so exciting, it is because it could have applications in cutting-edge technologies. The capacity of Dirac semi-fermions to behave differently depending on the direction could indeed open the way to more efficient and better performing materials in a multitude of areas. For example, this phenomenon could revolutionize batteries by making them more efficient or improving sensors used in high-tech devices.
THE Dirac semi-fermions share certain characteristics with the graphenea material that also has remarkable properties and is used in applications such as touch screensTHE supercapacitors and the solar cells. Furthermore, understanding how to exploit the properties of Dirac semi-fermions could make it possible to design new layered materials, the structure of which could be controlled with extreme precision, as is already the case for graphene.
The potential of these particles goes well beyond electronics. THE let's say could also find applications in technologies related to medicinelike the design of biomedical devices ultrasensitive. They could also be used in energy storage systems or even devices that would improve the performance of quantum computersa technology still in full development, but promising.
The remaining mysteries and next steps
Although Dirac semifermions have been observed, much remains to be understood. Scientists do not yet know everything about the behavior of these particles. Their appearance raises many questions, including how they interact with other particles and how their properties can be manipulated for practical applications.
Researchers have only scratched the surface of this strange phenomenon and still have much work to do to understand the mechanisms underlying phenomena that explain why certain directions allow these quasiparticles to move without mass while others make them massive. This research is still in its early stages and scientists hope that future discoveries will make it possible to better exploit this phenomenon to create new, more efficient materials.
In short, the discovery of Dirac semi-fermions is a perfect example of how fundamental science can lead to technological revolutions. Although this phenomenon is still difficult to fully understand, its future applications could transform many sectors.
