On the Construction of Optimal Asymmetric Quantum Codes
  Constacyclic codes are important classes of linear codes that have been applied to the construction of quantum codes. Six new families of asymmetric quantum codes derived from constacyclic codes are constructed in this paper. Moreover, the constructed asymmetric quantum codes are optimal and different from the codes available in the literature. 
Liqi Wang, Shixin Zhu
cs.IT math.IT