Quantum router could speed up quantum computers

Quantum computers may be able to execute useful algorithms more quickly, thanks to a new quantum router that helps data reaching the right place faster.

Traditional computers avoid becoming slow in front of a partly complicated program using random access memory (RAM) to temporarily store certain information. The key to the component to build a quantum RAM counterpart, Qram, is a router. It is not the router that directs your Internet requests to the right IP address, but rather an internal router that directs information traffic inside a computer.

Connie Miao at the University of Stanford in California and his colleagues have now built such a device. “The project was motivated by algorithms that use Qram. There were a lot of papers to come saying, “If we had an qram, we could do xyz”, but it had not been shown [experimentally]”, She said.

The new router consists of qubits, the basic elements of all quantum computers and quantum memories, made from tiny superconductive circuits and controlled by electromagnetic impulses. Similar to a traditional router, this quantum has sent quantum information to quantum addresses. What distinguishes the device as being entirely quantum is that it allows the address to be coded not only in a single place but in a superposition of two. The team tested this with three qubits and found that the route had around 95% loyalty.

This means that if it was incorporated into a Qram, the device could push information in a quantum state where it is impossible to say in which of the two locations in which it is stored – exactly the type of phenomenon that makes quantum computers powerful.

Luming Duan at Tsinghua University in China, the team of which previously built a quantum router that only worked during certain races, says that the new device is an important step towards the construction of practical Qram, which can make it possible to execute quantum automatic learning algorithms.

The member of the David Schuster team at the University of Stanford says that there are still many open questions on the place where quantum routing exactly could make a practical difference, but the options are wide, from algorithms well known for the search for databases when creating quantum IP addresses for future internet iterations.

However, the current version of the router is still not reliable enough for some of these uses, so it is necessary to make less errors and contain a greater number of qubits in the future, explains Sébastien Léger at the University of Stanford, which worked on the project.