'Light Speed' Electrons Discovered Moving in 4 Dimensions For The First Time

 Finally, an elusive behavior of electrons in a real-world substance has been separated from more commonplace electron activity.

Researchers at Ehime University, under the direction of physicist Ryuhei Oka, have measured what is known as Dirac electrons in bis(ethylenedithio)-tetrathiafulvalene, a superconducting polymer. These electrons can behave more like photons and oscillate at the speed of light because they are in an environment that effectively makes them massless.

According to the researchers, this finding will help us comprehend topological materials, which are quantum materials with an electrical insulator-like internal behavior and a conductor-like exterior.

The fields of semiconductors, topological materials, and superconductors are becoming more and more important, not to mention because of their possible uses in quantum computing. However, there is still a great deal we don't understand about these materials and their behavior.

Dirac electrons are plain old electrons under unusual circumstances that necessitate knowledge of special relativity to comprehend quantum behaviors. Here, atoms overlap and some of the electrons are propelled into an unusual region, enabling them to hop across materials with exceptional energy efficiency.

Developed from the nearly century-old equations of theoretical physicist Paul Dirac, we now know they exist because they have been found in graphene and other topological materials.

However, physicists encounter a problem while trying to comprehend Dirac electrons in order to fully utilize their potential. Dirac electrons cohabit with normal electrons, making it extremely difficult to clearly identify and measure one type of particle.

This was accomplished by Oka et al. by making use of an electron spin resonance characteristic. Because electrons are charged particles with a spinning distribution of charge, each one of them displays a magnetic dipole. Therefore, any unpaired electrons in a substance can have their spins affected by a magnetic field, changing their spin state.

Physicists can identify and examine unpaired electrons with this technique. Furthermore, as discovered by Oka and the other researchers, it may be utilized to directly monitor the behavior of Dirac electrons in bis(ethylenedithio)-tetrathiafulvalene, allowing them to be distinguished as distinct spin systems from ordinary electrons.

The group discovered that a four-dimensional description of the Dirac electron is necessary to completely comprehend it. The conventional three dimensions of space are the x, y, and z axes. An additional dimension is the electron's energy level, which is considered a fourth dimension.

"As 3D band structures cannot be depicted in a four-dimensional space," the authors of the report state, "the analysis method proposed herein provides a general way to present important and easy-to-understand information of such band structures that cannot be obtained otherwise."

These dimensions allowed the researchers to analyze the Dirac electron and come to a previously unknown conclusion. Their motion is not constant; instead, it is based on the material's temperature and magnetic field angle.

This suggests that we have added a new piece to the puzzle explaining the behavior of Dirac electrons, which could help us make better use of their characteristics in the future.