
'Fibonacci quasiparticle' could form basis of future quantum computers - jonbaer
http://phys.org/news/2014-12-fibonacci-quasiparticle-basis-future-quantum.html
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anigbrowl
I'm fascinated by Fibonacci #s and _phi_ *, aka the Golden Ratio, but Anyons,
Abelian-ness and braids are entirely foreign to me. Can anyone with more
knowledge opine on whether this is genius or quackery?

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gaze
Yo. I work in the field of quantum information. Usually you think of two
different types of particles, fermions and bosons which loosely correspond to
matter and force mediating particles. Electrons are fermions, and photons for
instance are bosons. Quarks are fermions and gluons are bosons of the strong
force. If I take two bosons and pick them up and switch their locations, then
nothing happens. If I have two fermions on the other hand and switch their
locations, their wave functions will acquire a 180 degree phase shift (or sign
flip, as you please) relative to the collective wavefunction of the two
particles in their original place.

Anyons are particles that acquire an arbitrary phase shift under exchange. You
might call exchange braiding in 2D, since you really are forced to make the
particles go AROUND each other. If you do the motion that people do when
playing the 3 shell game, if you think of the position of the particles'
location plotted in time, you'd kinda see a rope being braided out.

A nonabelian anyion is one for which the exchange is non-commutative. If I
braid A around B which has been braided around C, it's different than braiding
B around A which has been braided around C. Non-abelian just in general means
non-commutative, which just means that it's different if you do things in a
different order.

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anigbrowl
Wow, thanks for such a succinct yet informative reply.

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Sniffnoy
Reading the abstract on arXiv[0], it seems that what's new here is not the
idea of the Fibonacci anyon, which it was known could yield universal quantum
computation, but rather a possible scheme for realizing the Fibonacci anyon. I
say this explicitly because I didn't find that clear from the article.

[0] [http://arxiv.org/abs/1403.3383](http://arxiv.org/abs/1403.3383)

