Eric J. Heller, a physicist from the University of California Santa Cruz in 1984 proposed a hypothesis that electrons move in a quantum-space and follow a defined orbit instead of in an unorganized jumble. Researchers at the University of California Santa Cruz, around 40 years after the original discovery, confirmed the existence of “quantum marks” – unique orbits of electrons.
This new research, which was published in Nature, The electron’s particle- and wavelike properties are demonstrated. In the quantum world, electrons can behave in a way that is counterintuitive. Their waves can interact in some instances, influencing movement to certain patterns. They are known as unique closed orbits.
The researchers used a combination of imaging techniques with precise control over the electron behavior in graphene, to create patterns that resemble quantum scars. Graphene is a good candidate for quantum observations because of its unique properties.
The team created a trap using a probe with a very fine tip on a scanning microscopy. They then hovered the microscope probe near a graphene-coated surface in order to detect movement of electrons. The electrons were not physically disturbed.
Jairo Velasco, Jr., a co-author, says that as electrons travel from point A to B in a close orbit, they better preserve the properties of subatomic particles. The data encoded within the electron’s properties can be transmitted without any loss.
“This discovery could be used to process information. The electrons can be guided to travel across the device in a predictable manner by ‘nudging” or slightly disrupting their orbits.Velasco said.
Researchers can now explore the potential uses of Heller’s theories, as it has been proven. Since transistors already exist at the nanoelectronic level, using quantum scar designs can make them more efficient.
It could also enhance computers and smartphones, which rely heavily on transistors packed tightly to increase processing power.
“In future research, we will build upon our visualisation of quantum scars in order to develop methods for harnessing and manipulating scar states.Velasco said.
“By harnessing chaotic quantum phenomena, we can develop novel ways to deliver electrons selectively and in a flexible manner at nanoscale. This will allow us to innovate new methods of quantum control.”
The team also used a visual model of a Billiard to demonstrate the classic mechanics between linear and chaotic systems. The Billiard model is a bound area which reveals the movement of particles in an arbitrary shape known as a stadium. The ends of this shape are rounded and the sides straight.
The team used a 400-nanometer stadium billiard to create this experiment. The quantum chaos was demonstrated by scanning it using a tunneling microscopy. It is the first time that a pattern has been observed in the electron orbits of the stadium billiard.
Credit: Velasco Lab
“It is a great feeling to have successfully simulated quantum scars on a quantum system. These studies should help us understand chaotic quantum systems better.” said co-author Zhehao Ge.
Journal Reference
- Ge, Z., Graf, A. M., Slizovskiy, S., Polizogopoulos, P., Taniguchi, T., Watanabe, K., Van Haren, R., Lederman, D., I., V., Heller, E. J., & Velasco, J. (2024). Direct visualization of quantum scars by graphene quantum dots. Nature, 635(8040), 841-846. DOI: 10.1038/s41586-024-08190-6
