The performance of sequences of designed pulses of finite length Ï„ is
analyzed for a bath of spins and it is compared with that of sequences of
ideal, instantaneous pulses. The degree of the design of the pulse strongly
affects the performance of the sequences. Non-equidistant, adapted sequences of
pulses, which equal instantaneous ones up to O(Ï„3), outperform
equidistant or concatenated sequences. Moreover, they do so at low energy cost
which grows only logarithmically with the number of pulses, in contrast to
standard pulses with linear growth.Comment: 6 pages, 5 figures, new figures, published versio