  Ising-type non-Abelian anyons are likely to occur in a number of physical
systems, including quantum Hall systems, where recent experiments support their
existence. In general, non-Abelian anyons may be utilized to provide a
topologically error-protected medium for quantum information processing.
However, the topologically protected operations that may be obtained by
braiding and measuring topological charge of Ising anyons are precisely the
Clifford gates, which are not computationally universal. The Clifford gate set
can be made universal by supplementing it with single-qubit pi/8-phase gates.
We propose a method of implementing arbitrary single qubit phase gates for
Ising anyons by running a current of anyons with interfering paths around
computational anyons. While the resulting phase gates are not topologically
protected, they can be combined with "magic state distillation" to provide
error-corrected pi/8-phase gates with a remarkably high threshold.
