Abstract： We obtain a simplified and obvious expression of“concurrence” in Wootters’measure of entanglement of a pair of qubits having no more than two non-zero eigenvalues in terms of concurrences of eigenstates and their simple combinations. It not only simplifies the calculation of Wootters’measure of entanglement, but also reveals some general and important features. Our conclusions are helpful to further understand and application of quantum entanglement.
WANG An-Min. A Simplified and Obvious Expression of Concurrence in Wootters’Measure of Entanglement of a Pair of Qubits[J]. 中国物理快报, 2003, 20(11): 1907-1909.
WANG An-Min. A Simplified and Obvious Expression of Concurrence in Wootters’Measure of Entanglement of a Pair of Qubits. Chin. Phys. Lett., 2003, 20(11): 1907-1909.
2003, Vol. 20 
