The new approach will help quantum networks support more users without losing data. Details of the new quantum switch are being reported by researchers at Purdue University.
As quantum computers become more powerful and widespread, they will need a reliable quantum internet to communicate. Purdue University engineers have addressed an issue that is hindering the development of quantum networks.
The method, demonstrated in an article published in the journal Optica, will lay the foundation for Internet access for quantum computers, sensors, and other technologies.
The team deployed a programmable switch to regulate the amount of data flowing to each user by selecting and redirecting the wavelengths of light carrying different data channels. As a result, this allowed to increase the number of users without increasing the loss of photons as the network grows.
The point is, if photons are lost, quantum information is lost. This usually happens when photons travel long distances over fiber optic networks.
In a new study, scientists have shown a way to perform wavelength routing with just one device – a wavelength selectable switch. It will allow building a network of 12-20 users, and maybe more. Previous approaches required the physical replacement of dozens of fixed optical filters tuned to individual wavelengths. As a result, the regulation of communication between users became practically impractical, and the loss of photons – more likely.
Instead of adding these filters every time a new user joins the network, engineers can simply program a switch that selects the wavelength. This will direct the wavelengths of data transmission to each new user. As a result, operating and maintenance costs are reduced and the quantum internet becomes more efficient.
The wavelength selector switch can also be programmed to adjust the bandwidth according to the user’s needs. With fixed optical filters, this is simply not possible. Some users may use applications that require more bandwidth than others. For example, watching a show through a web streaming service uses more bandwidth than sending email.
For the quantum internet, shaping connections between users and throttling throughput means distributing entanglements, the ability of photons to maintain fixed quantum mechanical relationships with each other. Everything should work no matter how far apart they may be to connect users on the network. Entanglement plays a key role in quantum computing and quantum information processing.