Further analysis of some symmetric and antisymmetric composite pulses   for tackling pulse strength errors
  Composite pulses have found widespread use in both conventional Nuclear Magnetic Resonance experiments and in experimental quantum information processing to reduce the effects of systematic errors. Here we describe several families of time symmetric and antisymmetric fully compensating composite pulses, inspired by the previous Fn, Gn and BB1 families family developed by Wimperis. We describe families of composite 180 degree pulses (NOT gates) which exhibit unprecedented tolerance of pulse strength errors without unreasonable sensitivity to off-resonance errors, and related families with more exotic tailored responses. Next we address the problem of extending these methods to other rotation angles, and discuss numerical results for 90 degree pulses. Finally we demonstrate the performance of some 90 degree and 180 degree pulses in NMR experiments. 
Sami Husain, Minaru Kawamura and Jonathan A. Jones
quant-ph