Colloquium on March 29, 2010

Kirill Shtengel
University of California, Riverside

Non-Abelian anyons: New particles for less than a billion

The notion of quantum topological order has been a subject of much interest recently, in part because it falls outside of the well-established Landau paradigm whereby states of matter are classified according to their broken symmetries. Topologically ordered phases cannot be described by any local order parameter, yet they have many peculiar properties clearly distinguishing them from the conventionally disordered phases. For example, in two dimensions, they may support anyonic excitations - the quasiparticles that are neither bosons nor fermions. Moreover, anyons with *non-Abelian* braiding statistics are expected to occur, particularly in the fractional quantum Hall regime. In this talk, I will focus on solid state interferometers designed to detect such exotic statistics. I will discuss recent experiments in the the quantum Hall regime at 5/2 filling where the evidence for the existence of non-Abelian anyons may have in fact been observed for the first time. Interesting in their own right, such systems may also provide a platform for topological quantum computation. Quasiparticle interferometers will then become one of the key elements in such quantum computing schemes; I will address their potential applications in this context.