A theoretical analysis of recent experiments suggests that a key feature of a topological quantum computer—the unusual statistics of quasiparticles in the quantum Hall effect—may finally have been observed.
By exploiting the concept of particle-hole duality, one can realize a point junction between integer and fractional quantum Hall phases, which constitutes a crucial building block towards possible applications of the quantum Hall effect.
The fractional quantum Hall effect, thought to be special to two dimensions, may also flourish in three, providing a possible explanation for anomalies observed in certain 3D materials in high magnetic fields.
H. A. Fertig,
Physics2, 15 (2009) – Published February 23, 2009
Measurements of the heat transport at the edges of two-dimensional electron systems appear to provide explanations about the quantum Hall state that have not been forthcoming via charge transport experiments.
Physics1, 36 (2008) – Published November 24, 2008
The esoteric concept of “axions” was born thirty years ago to describe the strong interaction between quarks. It appears that the same physics—though in a much different context—applies to an unusual class of insulators.
Electrons in graphene can be described by the relativistic Dirac equation for massless fermions and exhibit a host of unusual properties. The surfaces of certain band insulators—called topological insulators—can be described in a similar way, leading to an exotic metallic surface on an otherwise “ordinary” insulator.