Direct measurement of the concurrence for two-qubit electron spin entangled pure state based on charge detection
Liu Jionga),b), Zhou Lana),c), Sheng Yu-Bo†a),b)
       
Relationship between Q and error probability. The coefficients of the initial state are and . The error probability P error1∈ [0,1] and P error2 ∈ [0,1], respectively. It is shown that if P error1 = P error2 = 0, then Q = 1. Meanwhile, Q = 0 if P error1 = 1 and P error2 = 0.