General asymptotic formulas for fixed-length quantum entanglement concentration

General formulas of entanglement concentration are derived by using an information-spectrum approach not only for i.i.d. sequences, but also for the general sequences of partially entangled pure states. From these formulas, not only can the achievable rates be calculated, but also the error exponents, resulting in a general relation between the performance of the entanglement concentration and the eigenvalues of the partially traced state.