Physicists accidentally discovered unusual quantum behavior of electrons using graphene and supernarial temperatures, opening new prospects in quantum technologies. Research conducted by specialists of the Massachusetts Institute of Technology (MIT), demonstrates the possibility of observing a phenomenon without the use of powerful magnetic fields, which was previously considered a necessary condition for such observations.
Electrons, although they are elementary particles, in the new experiment were “split” into fractional charges using ultra-thin layers of graphene and boron nitride, chilled to temperatures close to absolute zero. Usually, to achieve the so-called “fractional quantum effect of the Hall,” the creation of a constant magnetic field was required. However, a team of scientists from MIT demonstrated that it is enough to use simple materials such as graphene to observe the “fractional charge”.
During the experiment, the researchers folded five layers of graphene, each with a thickness of one atom, creating a stepped structure. These layers were clamped between two flakes of boron nitride, creating a lattice structure that imitated the effects of a magnetic field. After connecting the electrodes and cooling the system to temperatures close to absolute zero, the team observed an unexpected fractional charge phenomenon.
“When we first saw this, we did not find out at first. Then we began to scream from the realization how great it was. It was a completely unexpected moment,” – one of the co-authors of the study, assistant professor of physics at MIT, Long Yu. He noted that the “fractional charge” is such an exotic phenomenon that its implementation in such a simple system without a magnetic field can open the way to a new type of quantum computing more resistant to interference.
This discovery, published in the journal Nature, not only confirms the possibility of observing the “fractional quantum abnormal effect of the Hall” (abnormal here means “non-magnetic”) in crystalline graphene, but also opens up new prospects for research in quantum physics and the development of quantum technologies.