Physicists at the Australian National University and University of Otago have developed a prototype hard drive that can store gigabytes of quantum data for six hours, making it easier to send the data across the globe.
Through entanglement of photons – where one photon remains connected to the other no matter how far the distance – and using rare earth element europium embedded in a crystal, the data can be shipped to an overseas location before the memory or storage breaks.
“It’s kind of a quantum postal service,” explains Matthew Sellars, associate professor at the ANU Research School of Physics and Engineering.
The hard drive teleports quantum states and links up quantum computers, Sellars said.
“What you need for teleportation is entangled particles at two different locations. You can imagine with space craft, what you need is pairs of particles that are entangled. You keep one lot of pairs on Earth and the other you send of the spaceship. So that spaceship can go a long, long way away.
“By making measurements on the entangled particles, you can actually teleport a quantum state. But you need this entanglement there. What the hard drive allows you to do is store that entanglement long enough to make it interesting.
“Up until now the entanglement would disappear very quickly and your space craft wouldn’t get anywhere. We can store it for six hours and we think we can get a lot longer, so you can go the entanglement over much greater distances.”
Before ANU’s research breakthrough, quantum networks would usually be created through laser beams in optical fibres that would only allow for quantum states to be sent around 100 kilometres.
The team plans to extend six hours of storage to days so that quantum data can be sent to any location in the world. The europium crystal allows fragile quantum states to be unaltered for long periods of time.
“The two fields isolate the europium spins and prevent the quantum information leaking away,” said Dr Jevon Longdell of the University of Otago.
The hard drive has improved storage time by a factor of more than 100, according to ANU.