Physicists have designed the first machine to create negatively charged, massive particles, a breakthrough that could lead to an entirely new way of generating laser light using tiny amounts of energy.
The key to their success was creating a device that allowed them to create strange particles called polaritons. In this device, University of Rochester researchers arranged two mirrors to form an “optical microcavity.” Within that space, light is held at different colors of the spectrum, depending on the arrangement of the mirrors, according to a University of Rochester press release.
The researchers fitted a semiconductor made from two chemical elements, one metal and one nonmetal, into the microcavity. This particular semiconductor is roughly the width of an atom, less than one millionth the width of a human hair. The semiconductor was strategically positioned to interact with the trapped light. This interaction causes tiny exciton particles to be generated from the semiconductor, which combine with photons from the light. This mixing results in the formation of new hybrid particles called polaritons, some of which have negative mass. A paper describing the research was published in the scientific journal Nature Physics.
Negative mass is difficult to understand, both mentally and physically. Negative mass is a substance that behaves exactly the opposite way to how we would expect an object to behave. Whatever action we expect an object to take when a force is applied to it, the opposite action is taken by an object with negative mass.
“It’s kind of mind-bending when you think about it,” co-author Nick Vamivakas said in a press release, “because if you try to push or pull it, it goes in the opposite direction to your intuition.” Such matter is part of the theory of how wormholes work.
But these properties don’t negate the more general laws of physics. “People ask me if ‘negative mass’ means the device floats instead of falling with gravity, and that’s not what it means,” Vamivakas, an associate professor of quantum optics and quantum physics at the Rochester Institute of Optics, told Newsweek. “Negative mass is a property of particles within matter. The matter still has mass, and if you let go of it, it falls to the floor.”
Physicists believe polaritons could lead to a cheap, efficient way of conducting electricity: the strange particles they’ve created have an electric charge attached to them that can be manipulated to push or pull electric fields.
Vamivakas and his colleagues say they hope to use the device to create a low-power laser, one that doesn’t need to consume a lot of energy to produce the same amount of light. There have been a number of reports of negative mass in recent years, some of which have since been refuted. What makes this work different is that it creates charged polaritons, says Vamivakas, whose lab conducted the research. As far as he knows, all previous demonstrations of negative mass have used particles that have no charge, which makes them unsuitable for laser experiments.
“We want to push the limits of how efficient things can be,” Vamivakas says. “The particles have such light properties that they move around faster in matter than regular electrons. We’re trying to figure out how to make switches that use negative mass to turn things on and off in clever ways.”
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Newsweek is committed to challenging conventional wisdom, seeking common ground and finding connections.