Thursday, October 24, 2013

The Other Day Upon the Stair...

Last year, physicists at the CERN laboratory in Switzerland discovered proof of the Higgs boson, a subatomic particle which, by creating a Higgs field, gives mass to other subatomic particles -- meaning everything. Theorized in the early 1960s, the particle was undetected until technological advances allowed scientists to search for it and detect its existence.

Now some scientists in Switzerland, as well as some in France, have gone one better and found a particle that isn't actually there, which they are calling the "leviton." It was first theorized by Leonid Levitov in 1996.

Technically, the leviton is not a particle -- which means it, like the man upon the stair, isn't "there" in the sense that a person, platypus or proton is "there." It's a "quasiparticle," which is the name given to an effect which at the quantum level behaves in many ways as it would if a particle were there. If something walks like a particle and quacks like a particle but isn't a particle, then it's a quasiparticle.

The leviton is of interest to physicists because it shows up with the excitation of as little as one electron. Atoms in a metal or conducting material carry a current when they are excited by an energy source. Electricity applied to one end of a copper wire excites the electrons at that end of the wire, which in turn excites the electrons in the atoms next door, and so on, until it gets to the light switch at your house. Better conductors use more of that energy to keep the current flowing and lose less in the transmission.

A leviton is a quasiparticle that can get started with just one electron instead of a series of them, which means it takes a low level of energy to get it going and keep it going. Every transmission in modern technology, from electrical wires to information on computer microprocessors, has the transmission of current or energy at its root. The "wave" phenomenon of the leviton quasiparticle can do so with a very low level of energy, meaning potentially much smaller and more efficient electrical circuits

Levitov, as the story notes, is pleased the quasiparticle he predicted has been found, and said he is OK with the name, which he didn't pick. It's probably just as well they used his name, since the project head for the leviton discovery is named Christopher Glattli, and a "glattliton" would probably be pretty awkward to say.

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