Electron ‘Invisibility Cloak’ Could Lead to New Kinds of Electronics
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The same technique that is being used to make objects invisible to light could also help hide particles from passing electrons and lead to new kinds of electronics, scientists say.
Previous work on cloaking objects from view used so-called metamaterials made of manmade materials with unusual properties that can cause light beams to bend around an object and meet on the other side.
“We were inspired by this idea,” says Gang Chen, a mechanical engineering professor at MIT who decided to study how a similar technique might apply to electrons instead of light.
The concept developed by Chen and his team takes advantage of the fact that electrons travel through materials in a way that is similar to the motion of electromagnetic waves, including light.
In a computer model, the researchers simulated nanoparticles with a core consisting of one material and a shell made up of another. But unlike the case with light and metamaterials, the electrons do not bend around an object, but rather pass through it.
The electrons' paths get bent as they enter the particle, and then subsequently bend back when they re-emerge on the other side. The net result is as if the particle wasn't there.
The concept appears to work in theory, but the team will now try to build actual devices to see whether it performs as expected in real life.
“This was a first step, a theoretical proposal,” study team member Bolin Liao, an MIT graduate student, said in a statement. “We want to carry on further research on how to make some real devices out of this strategy.”
If it does work, it could lead to more efficient electronic filters or sensors, the researchers say. As the components on computer chips get smaller, Chen said, “we have to come up with strategies to control electron transport,” and this might be one useful approach.
The concept could also lead to new kinds of switches for electronic devices, Chen added.
The switch could operate by toggling between transparent and opaque to electrons, thus turning a flow of them on and off.
“We’re really just at the beginning,” he said. “We’re not sure how far this is going to go yet, but there is some potential” for significant applications.
The research is detailed in the current issue of the journal Physical Review Letters.