Quantum teleportation: from Chinese legends to Quantum Communication Zengle Huang

A Chinese Legend Monkey King’s body split (分身术) Wu Cheng-En (1501-1582) and “Journey to the west” Many interesting imagination related to modern physics: 天上一日，地上一年 (One day in heaven, one year on earth) Goku’s teleportation

Another Chinese Legend Selected as Nature’s 10 in 2017 Raise the record of quantum teleportation distance from ~100km to 1400km The aim of my presentation is to introduce his team’s experiment of transmitting the quantum state of a photon on Earth to a satellite in 2017. Jianwei Pan, Father of Quantum, Professor, University of Sci&Tech in China

Quantum teleportation The quantum state to be teleported is the polarization of the photon. e.g. |H>, |V> The state to be teleported: |Φ >1 = α|H>1 + β|V>1 Choose the entangled state: |Φ+ >23 = (|H>2|H>3+|V>2|V>3)/ 2 |Ψ>123 = |Φ >1 ⨂ |Φ+ >23 =|Φ+ >12 ⨂ (α|H>3 + β|V>3) =|Φ- >12 ⨂ (α|H>3 - β|V>3) =|ψ+ >12 ⨂ (β|H>3 + α|V>3) = |ψ- >12 ⨂ (β|H>3 - α|V>3) Alice can always select the results to be the entangled photons having the same polarization.

Single photon production: Ultraviolet 160fs laser pulses with repetition rate 80MHz Pulses pass through two BiBO crystals to produce photon1 and an entangled photon pair (parametric down conversion) Photon 1 and 2 are combined to perform a joint measurement; Photon 3 is sent to the satellite The photon 3 is measured by a polarization analyser, followed by two single photon detector. Fidelity: overlap between the correct teleported state |χ> and the measured density matrix ρ, F ≡ Tr( ρ| χ > < χ |)

Significance First experiment to teleport quantum states from ground to a satellite Greatly enhanced teleportation distance from ~100km to 1400km Long-distance teleportation between light and matter Global quantum network Can we teleport a photon from Beijing to NY via a satellite? Outlook