Interférences et corrélations quantiques Table des matières

x y
|xix|yiy
|xi −→ √t|xi+i√r|yi
|yi −→ √t|yi+i√r|xi.
t r t +r= 1
|xi −→ i|yi |yi −→ i|xi

t=r=1
2
BS :|xi −→ 1
√2¡|xi+i|yi¢
|yi −→ 1
√2¡|yi+i|xi¢.
eiφ
φ L
x
|xiBS1 −→ 1
√2¡|xi+i|yi¢
diff
−→ 1
√2¡eiφ|xi+i|yi¢
M
−→ 1
√2¡eiφ i|yi
|{z}
BS2
−→ 1
√2(|yi+i|xi)
− |xi
|{z}
BS2
−→ 1
√2(|xi+i|yi)
¢
BS2
−→ 1
2(−1−eiφ)|xi+1 2(−1 + eiφ)i|yi(∗)
=−eiφ/2cos(φ/2)|xi+eiφ/2sin(φ/2)|yi
cos α=1
2(eiα +e−iα) sin α=1 2i(e−iα −eiα)
|xiM−Z −→ −eiφ/2cos(φ/2)|xi+eiφ/2sin(φ/2)|yi.
x y
|xi |yit
r
x= cos2(φ/2) = 1
2(1 + cos φ) ;
y= sin2(φ/2) = 1
2(1 −cos φ).
φ x
φ= 0 y
φ=kL = 2πL/λ k λ
k p p = ¯hk

|xi. = ˆe1=
1
0
,|yi.
= ˆe2=
0
1
;
M(t). =
√t i√r
i√r√t
x
D(φ). =
eiφ 0
0 1
.
ˆe1M(1
2)D(φ)M(0) M(1 2)
M=M(1
2)M(0)D(φ)M(1 2) = −1 2
1 + eiφ −i(1 −eiφ)
i(1 −eiφ) 1 + eiφ
.
i
x y π/2
eiπ/2=i

|ψi=√t|xi+i√r|yi
|xi |yi
|xix
|ψi
φ= 0
eiφ/2
|ψieiθ|ψi
|xi+|yi |xi+eiθ|yi
t6=1
2