The potential for quantum computers is to do everything that a classical one can do and more. However, that doesn’t mean that they will replace them completely. The manipulation of qubits carries with it complex technological problems.

Inside Quantum Technology believes that both quantum and classical devices can work together, complementing each other. Quantum computers allow them to potentially solve certain problems much faster than any supercomputer and we think that practical results will be shown in the next couple of years. This achievement will be based on two important milestones – building a big enough quantum processor and developing sophisticated quantum algorithms.

**Current Processors**

The three largest companies building quantum computers are Intel, IBM and Google, with quantum processors operating 49, 50 and 72 qubits respectively. This naturally makes Google’s Bristlecone, revealed in March 2018, one of the strongest contenders in the race – Google is sure that its processor will be enough to demonstrate quantum supremacy.

Other companies are also building its own quantum computer and will surely produce impressive results once they’re done. Microsoft has established seven quantum labs in order to conduct experiments and work on exotic materials, while building a processor boasting 250 qubits. Rigetti Computing is another company that might claim the title of being the first to demonstrate quantum supremacy, with a promise in August 2018 to build a 128-qubit processor in the next 12 months.

**Finding the Right Algorithms**

Shor’s algorithm, although widely discussed whenever quantum computers are discussed doesn’t seem likely to be an early application — the current record for factoring a number is 21, set in 2012. It is clear that in the near future this algorithm is of little practical interest. Quantum computers have long since passed the stage of being seen primarily as scary devices capable of breaking the RSA scheme. Current focus has shifted to big data analysis and simulating materials.

The former could benefit from shallow-circuit algorithms discussed in a recent study by the researchers at IBM. They demonstrated proof that shallow-circuit devices will require a fixed number of steps to solve certain problems from linear algebra, regardless of the size of the input problem. For a classical counterpart the number of steps would inevitably increase. This proof has strong practical implications, since it shows an algorithm working on noisy qubits. All qubits have a certain coherence time during which operations with them can be performed, and increasing this time is no easy task. However, if the number of steps required for an algorithm is fixed and they can be finished quicker than the coherence time, this problem becomes much less relevant. Not to mention the relative ease with which such a setup can be scaled to bigger input sizes.

To learn more about quantum computers and when quantum supremacy will be shown, visit the Inside Quantum Technology Conference, which will be held at the Hynes Convention Center, Boston, March 19-21. Also, note that Inside Quantum Technology will soon be publishing a report on the major computing strategies of the leading vendors.

More information:

https://www.insidequantumtechnology.com/product/quantum-computing-strategies-2019/