Chinese Scientists Channel Star Trek And Beam Quantum Entangled Photons Into Space

"Beam me up, Scotty!" Chinese scientists just set a record for quantum entanglement distance, and many argue that this experiment expands the possibilities for global quantum communication.

The Chinese team of scientists, led by Ji-Gang Ren at the University of Science and Technology in Shanghai, fired a laser from a station in Tibet to a satellite 1,400 kilometers (870 miles) above the Earth’s surface. The laser that went to the satellite carried a photon that was entangled with another photon that remained on the ground. The scientists then entangled a third photon and measured their quantum states.

photon waves

“Entangled” photons have what Albert Einstein referred to as a “spooky connection”. Whatever action is performed on one particle affects the other particle as well. Furthermore, if scientists know the state of one of the particles, they will also know the state of the others. The information between the photons theoretically travels faster than the speed of light.

Another way to better understand photon entanglement is to pretend that you have cut a coin in half and sent the pieces to different people. The receivers of the coin halves would presumably know what the other half of the coin looks like without having to communicate with one another. It is important to note that this analogy is an oversimplification of a quite complicated quantum physics concept.

photon entanglement experiement
Image from: "Ground-to-Satellite Quantum Teleportation", Cornell University Library

Could this experiment have been conducted on earth? The short answer is no. The connection between entangled photons can be destroyed by a number of physical factors such as heat and vibration. Satellites are outside of the atmosphere and therefore present fewer opportunities to spoil or “observe” the connection between the entangled photons. Even still, many of the photons in this experiment were rendered unusable. The satellite only received 991 of the thousands of sent photons. 

This is not the first time that this team of scientists has been entangled in photon experiments. This past June, the group sent entangled photons from the Micius satellite to two ground stations. This previous experiment demonstrated that entangled photons can be sent over long distances while the most recent experiment revealed that a photon’s quantum state can also be transmitted.

Although human beings will probably not be teleported any time soon, this experiment is a step toward quantum communication or the movement of small bits of information. It is important to note that while this study has been published online, it has yet to be peer-reviewed outside of China or replicated. You can learn more here.