What is the “Proposed” Concept of Distributed Quantum Computing?
Lets say you have 10 Quantum Computers each with a 10 Qubit Capacity (like what we have today). So in total they have 100 usable Qubits. Lets say you have a problem to solve which requires 100 Qubits. You breakup the problem in such a fashion that each quantum computer processes a small part requiring 10 qubits and then you aggregate the solutions together to get the final answer.
There is a huge huge problem with that.
What is the problem?
Well Quantum Computers are being built for a reason. And that is to solve the most difficult problems which we have which cannot be solved with Classical Computers. And ‘all’ such problems have one problem. They cannot be broken up into parts, solved in parts and the results aggregated into the final ‘perfect’ solution. If that was possible then these problems would have been solved already.
So basically, this concept of Distributed Quantum Computing won’t work.
But, there is a twist to the story. What is that?
Proponents of DQC say that by distributed we mean just 10 meters. All these QC’s are separate physical entities but they are kept only 10 meters apart in the same room.
OK. Then what?
Then the second twist is that the proponents claim that instead of breaking up the problem into 10 parts. We will integrate all the Quantum Computers such they function as one logical quantum computer with 100 qubits. Then they will be able to solve the 100 Qubit problem? right?
Well, theoretically yes! If such an integration is possible. Which maintains All-To-All Qubit connectivity, coherence times and precision.
So what do we have to do to make this possible?
First of all, such an integration is not possible with Superconducting Qubits because we cannot move them around. It is also not possible with Ion Qubits for the same reason. It might just be possible with Photonic Qubits. Because we can move entangled photons around.
At Automatski we believe in solving the low hanging fruit first. Nobody outside Automatski has a working quantum computer (Well, crapware and vaporware aside).
So basically lets put all our money and efforts in building a ‘Single Piece’ Quantum Computer before fantasizing about Distributed Quantum Computing.