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Physicists Say They've Created a Device That Generates 'Negative Mass'
Physicists have created what they say is the first device that's capable of generating particles that behave as if they have negative mass. The device generates a strange particle that's half-light/half-matter, and as if that isn't cool enough, it could also be the foundation for a new kind of laser that could operate on far less energy than current technologies.
This builds on recent theoretical work on the behaviour of something called a polariton, which appears to behave as if it has negative mass – a mind-blowing property that sees objects move towards the force pushing it, instead of being pushed away.
Now physicists from the University of Rochester have created a device that allows them to actually create these polaritons at room temperature. They do this by manipulating captured photons and combine them with a kind of quasi-particle called an exciton to make something half-light/half-matter that some scientists affectionately refer to as 'magic dust'.
This alone is "interesting and exciting from a physics perspective," says quantum physicist Nick Vamivakas from Rochester's Institute of Optics. "But it also turns out the device we've created presents a way to generate laser light with an incrementally small amount of power."
Anomalous dispersion of microcavity trion-polaritons (open, DOI: 10.1038/nphys4303) (DX)
Previously: Physicists Create 'Negative Mass'
(Score: 5, Interesting) by maxwell demon on Tuesday January 16 2018, @12:45PM
Since you have to add a photon (positive energy), you end up with a state that has more total energy, and thus more total mass (as E=mc²). The negative mass is only the effective mass of the quasiparticle describing its movement relative to the material. It is mostly unrelated to the real mass that enters the inertia/gravity of the material as a whole.
As an example, take the most common (and most easy to understand) quasiparticle: The hole. The hole is just a missing electron, no electron sitting where an electron should be. No electron of course has less real mass than one electron. Yet a hole has a positive effective mass; it behaves exactly as if there were a particle with positive mass and opposite charge sitting in that place (and indeed, the mass can even differ depending on the direction the hole moves!).
The Tao of math: The numbers you can count are not the real numbers.