Link-layer Protocol Could Bring a Quantum Internet Sooner Rather Than Later

World’s first link layer protocol brings quantum internet closer to a reality

Excerpts and salient points ~

+  In classical computing, a collection of software layers referred to as the network stack allows computers to communicate with each other. Underlying the network stack are communications protocols, such as the internet protocol or HTTP. Stephanie Wehner explained that one essential protocol used by a network is the link layer protocol, which overcomes the problems caused by imperfect hardware: “All of us use classical link layer protocols in everyday life. One example is Wi-Fi, which allows an unreliable radio signal—suffering from interruptions and interference—to be used to transmit data reliably between compatible devices.”

“Our link layer protocol allows us to reliably generate entanglement between two network nodes connected by a direct physical link, such as a telecom fiber. The next step is to produce entanglement between network nodes which are not connected directly by a fiber, using the help of an intermediary node. In order to realize large scale quantum networks, it is important to go beyond a physics experiment, and move towards building a quantum network system. This is one of the objectives EU-funded Quantum Internet Alliance (QIA).”

+  It turns out that existing classical protocols cannot help in the quantum world. One challenge is presented by differences between the technologies used. Stephanie Wehner: “Currently, qubits cannot be kept in memory for very long. This means control decisions on what to do with them need to be taken very quickly. By creating this link layer protocol, we have overcome obstacles presented by some very demanding physics.”

Image: Using the link layer protocol, higher-layer software can request the creation of entanglement without needing to know which quantum hardware system is in the box. (Image Credit: QuTech/Scixel)

+  Researcher Matthew Skrzypczyk said that an important feature of the proposed quantum network stack and the link layer protocol is that it any future software written using the protocol will be compatible with many quantum hardware platforms. “Someone who makes use of our link layer protocol no longer needs to know what the underlying quantum hardware is. In our paper, we study the protocol’s performance on Nitrogen-Vacancy centers in diamond, which are essentially small quantum computers. However, our protocol can also be implemented on Ion Traps, for example. This also means our link layer protocol can be used in the future on many different types of quantum hardware.”

Source:  PHYS.ORG.  Delft University of Technology,  World’s first link layer protocol brings quantum internet closer to a reality…

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