We may be a step closer to unhackable quantum Wi-Fi thanks to a chip that could establish wireless communication between a wide range of quantum devices.
Quantum communication systems have a distinct advantage over the wireless and fibre-based networks that we use now: they are incredibly hard to hack. This is because they use the quantum states of objects like particles of light to encode and transmit information 鈥� those states allow for more complex encryption and can easily reveal if they have been tampered with.
Such networks already exist on a small scale. In recent years, they have been built in cities with existing fibre cables, and space agencies have launched quantum communication satellites. But building out a broad, wireless quantum network has been challenging, partly because quantum signals are easily corrupted as they travel through the air between emitting and receiving antennas.
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Now, at the California Institute of Technology and his colleagues have built a system on a chip called a 鈥渜uantum phased array鈥� (QPA) that could make it easier to set up quantum Wi-Fi anywhere.
The QPA crams more than 1000 electronic components onto a silicon-based chip only 1.8 millimetres wide and 3 millimetres long. That includes 32 tiny antennas that can pick up and emit the quantum signals that move through free space. The device is built similarly to conventional computer chips, so it works at room temperature instead of having to be kept very cold in specialised fridges 鈥� as is the case for many quantum communication devices.
In one experiment, the researchers used a laser to transmit a signal of squeezed quantum light, which has unusually precisely tuned properties, to test the chip鈥檚 ability to receive and analyse quantum information. They could also program the QPA鈥檚 antennas for real-world uses, such as only detecting signals from certain directions and extracting as much information as possible from a noisy signal.
Additionally, the team used the QPA to pick up a signal and change its quantum properties to make it more compatible with any quantum device, like a quantum computer or a sensor, that the chip may be integrated with.
鈥淭his is a technical advance,鈥� says at the University of York in the UK. He says that, if the new device could eventually establish quantum-encrypted wireless communication inside of buildings, it could mirror existing communication technologies 鈥� with an added layer of security. This could be especially relevant for the ever-increasing number of devices comprising the so-called Internet of Things, which are often vulnerable to hackers, he says.
Ottaviani says that the QPA is an exciting step in the right direction, but more technical improvements are needed before full-fledged quantum Wi-Fi becomes reality. For instance, the chip will have to become better at accurately picking up quantum light from far away. 鈥淏ut I see a bright future for this 鈥� the future is clearly quantum,鈥� he says.
arXiv
