Editor's Summary
17 April 2008
Doing it by quarters
A quantum computer relies on 'qubits' (or quantum bits) which can be in a quantum state that implies the qubit is both '0' and '1' at the same time. But for conventional qubit designs, typically based on a single particle such as an electron or photon, these quantum states are vulnerable to disturbances and can be easily lost. There is a hypothetical alternative: the topological qubit, which would hold information as a series of 'braids' formed of two-dimensional quasiparticles. This new form of computing comes a step closer with the publication of compelling evidence for the existence of 'e/4' quasiparticles of the type that could transform topological quantum computers from the hypothetical to the proof-of-principle stage. In a News Feature, Liesbeth Venema explains some of the background to this exciting field.
News and Views: Quantum physics: Debut of the quarter electron
A particle-like object with a quarter of an electron's charge is the latest find in a hotbed of quantum-physical experimentation, the fractional quantum Hall fluid. Its significance is more than esoteric.
Eduardo Fradkin
doi:10.1038/452823a
Article: Observation of a quarter of an electron charge at the 
= 5/2 quantum Hall state
M. Dolev, M. Heiblum, V. Umansky, Ady Stern & D. Mahalu
doi:10.1038/nature06855
Abstract | Full Text | PDF (1,244K) | Supplementary information