This week's colloquium in Physics & Astronomy

BFG COMPOSITE ROTATIONS: PRECISE CONTROL IN AN IMPRECISE WORLD

   Jonathan Jones  

University of Oxford

18 May 2012  

Quantum information processing technologies are notoriously vulnerable to the effects of errors. These include not only random errors (decoherence) but also systematic errors arising from experimental imperfections. Composite rotations, originally developed in NMR where they are called composite pulses, provide an effective way of tackling systematic errors in many cases, allowing precise control of quantum systems with ordinary imprecise equipment. After a simple introduction to the basic ideas, Prof Jones will describe BB1 composite rotations, and finally the recently discovered family of BFG rotations which allows extreme tolerance of errors in certain cases.