A compact device that manipulates atoms to store quantum informationĀ could be a step towards building a quantum internet that could transmit exceptionally secure information across fibre-optic cables.
Devices that store quantum information, known as quantum memory, often consist of a maze of small components strewn across large tables, and typically require high vacuum or extreme cooling technology that can be sensitive to the tiniest of disturbances.
Now, and his colleagues at the quantum communication start-up Qunnect in Brooklyn, New York, have made a quantum memory device that is about the size of a pizza box and its early tests show that it could work well outside of the controlled conditions of the lab.
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Information is input into this quantum memory in the form of single particles of light, or photons, that travel through an optical fibre. As a photon enters the box it is directed by lens-like devices into a small container filled with a vapour of rubidium atoms. This changes the atomsā quantum states and effectively encodes the information carried by the photon into the vapour. The output of the memory is also light, which leaves through another fibre.
The device doesnāt have to be cooled or put into vacuum. Currently, information stays legible within the memory for about 0.8 milliseconds after being stored, after which the atoms start to spontaneously transition into states other than the ones chosen for the original encoding.
Namazi says that most other quantum memories that are not kept at very low temperatures can store information carried by a single photon for a few microseconds ā about a hundredth of the storage time of his teamās device.
at the Australian National University in Canberra says that the mechanism for storing information in the new memory is well established, but its design improves its practicality. He says that the new device is packaged so that it would easily fit into existing telecommunication hubs.
āThe team has done some great work showing that it is actually possible to put the components you need for a quantum memory in a small enough space for eventual deployment outside the lab,ā says Buchler.
But he says that the wavelength of light used by the new device is not yet compatible with existing telecommunications networks, and that it also does not store information with high efficiency right now.
at Qunnect says that for a quantum internet to be possible, everyone will need one of these devices. The goal is to make the device be a box that anyone could install in a normal room, he says.
Reference: Physical Review Applied,
