An idea of hybrid maps is proposed to establish standard entanglement
purification protocols which guarantee to purify any distillable state to a
desired maximally entangled pure state all by the standard purification local
operations and classical communications. The protocols proposed in this work,
in which two state transformations are used, perform better than the IBM and
Oxford protocols in the sense that they require fewer operation times in
yielding a same amount of the desired pure state. One of the proposed protocol
in this work can even lead to a higher improved output yield when it is
combined with the hashing protocol, as compared with the combined algorithm
consisting of the Oxford and the hashing protocol.Comment: 4 figures, 10 page