Whatever their underlying technology, to achieve scale, quantum computers will need to go modular and be networked. In 2021 we will see the first demonstration of this.
Quantum technology is often linked to three different areas of networking. The first is to improve the security of the internet, by adding quantum encryption to its communications technology. Second is to build tomorrow’s internet using next-generation quantum technology. And the third is to build more powerful quantum computers. It’s in this third area where we will see a significant advance.
There are two proven ways to build a faster, more powerful computer. The first is to increase the performance of individual components, such as the speed of the processor. The second is to go modular and increase the number of components, adding, for example, multiple processors. IBM’s Summit supercomputer uses this second approach. It is the size of two tennis courts and has 9,216 processors boosted by 27,648 graphics processing units.
The same two approaches apply to quantum computers. IonQ, IBM, Google and others are working on bigger and better quantum processing units (QPUs), the equivalent of CPUs in traditional computing. But it is also possible to get to scale by simply building more quantum computers and “networking” them, as we see with the cloud today. As your computational needs increase, the number of servers escalates to meet the demand. If you have a 100 qubit QPU and your application needs 2,000 qubits, you can simply “network” 20 QPUs together to create a cluster that acts as a single, more powerful quantum computer.
In “classical” computing, going modular often incurs some sort of penalty in terms of performance, or additional overhead cost in terms of both money and time. However, to allow multiple quantum computers to work together, we must entangle qubits across QPUs. Entanglement allows two qubits to remain connected so that actions performed on one affect the other, even when separated by great distances. After the qubits are entangled, they no longer care about locality, distance or source of the qubit, meaning there is no overhead to running them after the initial setup cost.
In 2021, we will see the first demonstration of modular quantum computers that are “networked” for the purpose of building a single, but much larger, example. This will happen in the real-world quantum industry, outside of theoretical experiments in academic labs, and will show us a clear path towards creating more powerful quantum computers.
Peter Chapman is CEO and president of quantum-computing startup IonQ
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