In a world where technology is evolving at breakneck speed, scientists are constantly searching for new materials that can overcome the limitations imposed by the traditional electronics used today in our computers and smartphones.
Our current devices rely mainly on controlling the movement of electrical charge in electrons to exchange and store information, but traditional methods are gradually approaching their maximum limits in terms of processing speed, as they have reached significant levels of heat resulting from operation and energy consumption.
In a landmark scientific step that lays the foundation for the future of highly efficient computing, a recent study published in the journal Physical Review Letters revealed unprecedented potential for extremely thin atomic materials. This research was led by an international team that demonstrated that precise chemical engineering of these materials multiplies their capabilities beyond expectations.
Microscopic dance floor
The new study focuses on a family of modern atomic materials known technically as transition metal dichalcogenides.
Ahmed Qasim, a researcher in the Department of Chemistry at Virginia Commonwealth University in the United States and not involved in the study, said in exclusive statements to Al Jazeera Net: “They are crystalline materials that can be reduced to sheets with a thickness of only one atom,” which makes them thousands of times thinner than a human hair. These 2D materials have properties that make them ideal for an emerging technical field called valley electronics.”
In this field, scientists do not rely on the movement of electrical charge, which may cause the devices to heat up. Rather, they exploit specific energy levels within the atoms of matter that serve as storehouses for storing electron information.
These valleys can be used to store data, opening the door to processing information at tremendous speeds while greatly reducing thermal waste. But the biggest challenge was how to precisely control these valleys using magnetic fields.
Ahmed says: “The researchers found that by mixing two similar materials in precise proportions, they can produce a new material that shows completely different behavior in the magnetic field, far exceeding the response of either material individually.”
To understand what scientists have discovered, we must learn about a physical concept called the exciton. When light hits this two-dimensional material, it gives energy to one of the electrons and causes it to leave its place, leaving behind a positively charged hole. This negative electron is attracted to the positive gap and they begin to move together like a pair on a microscopic dance floor, and this pair is the exciton.
Ahmed comments: “Excitons in dichalcogenides are particularly interesting due to their remarkable stability and efficient photoemission. This property makes them promising candidates for the development of LEDs, solar cells and future quantum devices.”
Magic magnetic mixture
The interaction of these dancers with any external magnetic field is measured by an index known as the “G-factor,” which is simply a measure of the strength of a material’s response to a magnet. In ordinary pure materials of this family, such as molybdenum selenide or tungsten selenide, the strength of this response is equal to the number 4 with a negative sign indicating the direction of the reaction.
The researchers decided not to be satisfied with pure materials and mixed the two materials in precise proportions to make 5 hybrid alloys to compare the extent to which these properties changed. “The five alloy compositions examined contained approximately 23%, 46%, 49%, 68%, and 85% molybdenum and the remainder tungsten,” Ahmed says. “Each monolayer was then sandwiched between thin layers of a protective, electrically inert material, resembling bubble wrap at the nanoscale.”
When scientists applied strong magnetic fields to these alloys, they noticed that in the alloy containing between 20-25% molybdenum, the absolute G-factor strength jumped significantly from 4 to 10.
This change means that the actual strength of the material’s sensitivity to the magnetic field has increased two and a half times compared to the original material, giving scientists tremendous magnetic control ability to direct data transmission paths.
To explain the reason for this dramatic change, the research team used theoretical computer calculations to simulate the behavior of electrons. Models have shown that the chemical mixing of atoms led to the merging of energy levels, as if the personalities of the different atoms had blended and formed a new quantum character that was much stronger than their individual parts.
“This behavior can be likened to mixing red and blue,” Ahmed explains. “Instead of getting a smooth gradation through violet, we end up with a striking dark violet color, much more intense than either of the original colors at the right mixing ratio.”
The importance of this discovery goes beyond improving traditional phones or computers and reaches the core of the development of quantum computing. In quantum computers, scientists rely on data units called qubits that require highly precise magnetic control.
The high magnetic responsiveness of these alloys makes them an ideal platform to control these qubits more efficiently, contributing to the stability of quantum calculations.
