Quantum Entanglement

In this week’s piece on potentially transformative technology, I have selected a further extension of the quantum computing topic. The concept I will touch on was well described by Albert Einstein as “Spooky Action at a Distance”. This quantum property is called “Quantum Entanglement”. It is a bizarre property of quantum particles where they become entangled through physical interaction or through external forces like a laser. What does this actually mean? Essentially, what is observed of one particle will give you information about what the other particle is doing. If the one is observed to be spinning in one direction, so will the other no matter how far apart they are – it could be 10 light-years away.

Without going into more technical detail that may put you to sleep, how is this used or proposed to be used practically?

The main areas of research and usage are quantum computing, quantum cryptography/ secure comms and quantum teleportation (beam me up Scotty’ish). I will touch on quantum cryptography for secure high-speed communications. Firstly, current high-speed comms using fibre is dependent on the transmission of light down a glass fibre at the speed of light. Since light requires energy for transmission, its signal degrades over distance and so repeaters that boost the signal are required along the way. These comms are also not completely secure. The comms may be encrypted but can be intercepted and potentially decrypted – not trivial but possible. The theory with quantum communication is that the quantum state of particles along the “comms line” would be entangled using perhaps a “laser”, the series of entangled nodes would then reflect the transmitted information at each end through the manipulation of the quantum state at the sender’s end. This doesn’t require anywhere near the same power requirement as fibre and is impossible to decrypt as any interference/ observation in the “chain” would destroy the information. This sounds fantastical, right? Well, currently it is pretty theoretical like many of the ideas in this domain. Quantum teleportation has been shown as possible in a laboratory, but we are light years away from teleporting anything physical. While quantum communications and teleportation are far from being useful yet, the properties of quantum entanglement are used in quantum computing practically.

Science fiction is becoming a science fact.