The Old Assumption
For anyone who has ever sat down and paid attention in Chemistry class, you will remember something when I bring up electrons, van der Waals forces, or even atomic levels. Electrons are the microscopic negative particles in an atom that are capable of movement. Van der Waals forces are the quantum forces of attraction that act between two different particles regardless of the charge, while atoms are the smallest forms of an element that can take part in a chemical reaction.
In the past, it was assumed that an electron would move from the top energy level to the lower atomic level in an atom. A team of scientists from the University of Kansas has however published a paper that could put an end to this theory.
Research Refutes Formerly Acknowledged theory
The team, led by researcher Hui Zhao, used a 2 D design of three layered materials to conduct their research. The materials used were MoS2, WS2, and MoSe2 due to their superconductivity, or low resistance to current. They were layered and exposed to different colored lights. Each material emitting electrons only when exposed to a particular colored light was cited as the reason for this use of various lasers.
In the experiment, the first layer, also known as the top layer, was exposed to the required ultra-short laser beam. The electrons in that layer were then liberated.
The team then observed the movement of these electrons. “We used another laser pulse with the ‘right’ color for the bottom MoS2 layer to detect the appearance of these free electrons in that layer. The second pulse was purposely arranged to arrive at the sample after the first pulse by about one picosecond (a trillionth of a second) by letting it travel a distance 0.3 mm longer than the first.”
It was noted that the electrons from the top layer appeared in the bottom layer after about one picosecond on average. But this was not all the researchers recorded.
The team later discovered that when they used the ‘right’ light for the second layer, no electrons could be observed moving through the layer as they traveled from the top atomic level to the bottom one. It was as if the electrons had ‘disappeared from the topmost level and ‘reappeared in the lowest atomic layer. Zhao had this to say about the bizarre behavior of the electrons. “It is as if electrons showed up on the first floor, then on the third floor, without ever having been on the second floor.”
The work of this team was augmented when another team of researchers from the University of Nebraska-Lincoln also recorded similar results in their lab.
The Implications
With the discovery of this ‘appearance’ and ‘disappearance’ of electrons between various atomic levels come various possibilities. Scientists can utilize the phenomenon to combine different nanomaterials to produce materials with more useful new properties, the electronics industry may benefit from better superconductors, and soon, we may have faster and more affordable computers.
