D. Bouwmeester et. al. Nature (1997) Joep Jongen. 21th june 2007

Transcription

1 al D. Bouwmeester et. al. Nature (1997) Universiteit Utrecht 1th june 007

2 Outline

3 EPR Paradox 1935: Einstein, Podolsky & Rosen Decay of a π meson: π 0 e + e + Entangled state: ψ = 1 ( + + )

4 EPR Paradox 1935: Einstein, Podolsky & Rosen Decay of a π meson: π 0 e + e + Entangled state: ψ = 1 ( + + )

5 EPR Paradox 1935: Einstein, Podolsky & Rosen Decay of a π meson: π 0 e + e + Entangled state: ψ = 1 ( + + )

6 Bouwmeester et. al. Teleport of a quantum state ψ from Alice to Bob. After a measurement on ψ lots of information is lost. Focus on quantum state of photon, with a basis of two orthogonal polarizations. ψ = α + β

7 Bouwmeester et. al. Teleport of a quantum state ψ from Alice to Bob. After a measurement on ψ lots of information is lost. Focus on quantum state of photon, with a basis of two orthogonal polarizations. ψ = α + β

8 Bouwmeester et. al. Teleport of a quantum state ψ from Alice to Bob. After a measurement on ψ lots of information is lost. Focus on quantum state of photon, with a basis of two orthogonal polarizations. ψ = α + β

9 Bouwmeester et. al. Teleport of a quantum state ψ from Alice to Bob. After a measurement on ψ lots of information is lost. Focus on quantum state of photon, with a basis of two orthogonal polarizations. ψ = α + β

10 System

11 First photon with Alice in state: Three photon system ψ 1 = α 1 + β 1 Combine with a entangled pair (photon & 3) in antisymmetric state: ψ 3 = 1 ( 3 3 ) Preform a measurement on photon 1 & Projection also entangled antisymmetric state: ψ 1 = 1 ( 1 1 ) ψ 1 opposite ψ & ψ opposite ψ 3 ψ 1 = ψ 3

12 First photon with Alice in state: Three photon system ψ 1 = α 1 + β 1 Combine with a entangled pair (photon & 3) in antisymmetric state: ψ 3 = 1 ( 3 3 ) Preform a measurement on photon 1 & Projection also entangled antisymmetric state: ψ 1 = 1 ( 1 1 ) ψ 1 opposite ψ & ψ opposite ψ 3 ψ 1 = ψ 3

13 First photon with Alice in state: Three photon system ψ 1 = α 1 + β 1 Combine with a entangled pair (photon & 3) in antisymmetric state: ψ 3 = 1 ( 3 3 ) Preform a measurement on photon 1 & Projection also entangled antisymmetric state: ψ 1 = 1 ( 1 1 ) ψ 1 opposite ψ & ψ opposite ψ 3 ψ 1 = ψ 3

14 First photon with Alice in state: Three photon system ψ 1 = α 1 + β 1 Combine with a entangled pair (photon & 3) in antisymmetric state: ψ 3 = 1 ( 3 3 ) Preform a measurement on photon 1 & Projection also entangled antisymmetric state: ψ 1 = 1 ( 1 1 ) ψ 1 opposite ψ & ψ opposite ψ 3 ψ 1 = ψ 3

15 First photon with Alice in state: Three photon system ψ 1 = α 1 + β 1 Combine with a entangled pair (photon & 3) in antisymmetric state: ψ 3 = 1 ( 3 3 ) Preform a measurement on photon 1 & Projection also entangled antisymmetric state: ψ 1 = 1 ( 1 1 ) ψ 1 opposite ψ & ψ opposite ψ 3 ψ 1 = ψ 3

16 First photon with Alice in state: Three photon system ψ 1 = α 1 + β 1 Combine with a entangled pair (photon & 3) in antisymmetric state: ψ 3 = 1 ( 3 3 ) Preform a measurement on photon 1 & Projection also entangled antisymmetric state: ψ 1 = 1 ( 1 1 ) ψ 1 opposite ψ & ψ opposite ψ 3 ψ 1 = ψ 3

17 Projection of photon 1 and on entangled state Photon 1 and are send trough a beam splitter. The probabilities for both reflected or transmitted must be added in QM. For symmetric states probability is 0. Only antisymmetric state is detected. (5%)

18 Setup

19 Method Photon 1, set to a polarization. Photon &3 in entangled pair state from EPR Source. Detect d1f1f or df1f simultaneously. Time delay is controlled by creation photon pairs. Photon 4 is used for single photon measurement.

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21 Different Polarizations Polarization Visibility ± ± ± ± 0.0 Circular 0.57 ± 0.0

22 With detection of photon 4 added.

23 The state from photon 1 can be teleported to photon 3. Classical information is still needed for 5% chance.

24 Questions?