国家重点实验室 Example:BEC o For N=4, X C(W0)=1-e=0.5 C(W,0=C(W0)2=0.25 C(W22)=2C(w,9)-C(w)2=0.75 C(W)=C(W)2=0.0625 W W C(W2)=2C(W,)-C(W2)2=0.4375 C(W)=C(W,2)2=0.5625 C(W)=2C(W2)-C(W2)2=0.9375 24Example: BEC For N=4, 24 ( ) 1 1 C W( ) 1 0.5 =− = ε () () 1 1 2 2 1 CW CW ( ) ( ) 0.25 = = ( ) () () 2 11 2 2 11 CW CW CW ( ) 2 ( ) ( ) 0.75 =−= () () 1 1 2 4 2 CW CW ( ) ( ) 0.0625 = = ( ) () () 2 11 2 4 22 CW CW CW ( ) 2 ( ) ( ) 0.4375 =−= () () 3 2 2 4 2 CW CW ( ) ( ) 0.5625 = = () () () 4 22 2 4 22 CW CW CW ( ) 2 ( ) ( ) 0.9375 =−= W W W W X1 X2 U1 U2 Y1 Y2 X3 X4 U4 U3 Y3 Y4 G 4 W4