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.
Physics2, 24 (2009) – Published March 30, 2009
The surprising prediction that currents can flow forever in small normal metal rings was confirmed almost twenty years ago. Highly precise new experiments find good agreement with theory that was not seen till now.
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.
Crystalline structures have been observed in nanoislands of electrons floating above superfluid helium. The energy required to add or subtract an electron from these quantum-dot-like islands agrees well with theory.
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.
Graphene has been idealized as a two-dimensional electron system in which the electrons behave like massless fermions, but how “perfect” is it? Scientists now show they can prepare free-standing sheets of graphene that have some of the highest electron mobilities of any inorganic semiconductor.
A decade ago, experimentalists showed that persistent currents can flow in nonsuperconducting mesoscopic metal rings, but there was no theory that correctly explained the magnitude or direction of the unexpectedly large currents. Theorists are now proposing a simple idea that may at last explain these results.
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.