Topological quantum computer A topological quantum computer is a
theoretical quantum computer that employs two-dimensional
quasiparticles called anyons, whose world lines cross over one
another to form braids in a three-dimensional spacetime (i.e.,
one temporal plus two spatial dimensions). These braids form the
logic gates that make up the computer. The advantage of a
quantum computer based on quantum braids over using trapped
quantum particles is that the former is much more stable. The
smallest perturbations can cause a quantum particle to decohere
and introduce errors in the computation, but such small
perturbations do not change the topological properties of the
braids. This is like the effort required to cut a string and
reattach the ends to form a different braid, as opposed to a
ball (representing an ordinary quantum particle in four-
dimensional spacetime) simply bumping into a wall. The original
proposal for topological quantum computation is due to Alexei
Kitaev in 1997. While the elements of a topo