One of the most frequently asked questions is what applications will be good targets for quantum computers. In general, this question has been answered at a high level with general descriptions like computational chemistry, financial applications, optimizations, quantum machine learning, etc.

So we were quite interested to see a presentation from IBM that went deeper and described not only specific use cases within these general areas, but also provided some visibility on the relative time frames when they expected these use cases may become possible. IBM has graciously permitted us to show a summary of this analysis to our readers including several charts they provided that you can see below.

Starting at the top level, they have divided the various use cases into different algorithm families and provided the main uses and examples as shown below.

The next step is to provide an estimate of what algorithms may be applicable for each of these families. The following chart shows where certain algorithms could be best applied for the different algorithm families described above. Note that the first two, VQE and QAOA, are particularly well-suited for the NISQ level machines that we expect to be available in the near term.

Since the primary customer targets for quantum computing are various enterprises in different industry sectors, the next slide maps the different algorithm families to specific use cases with the industry sectors.

And finally, it is very helpful to understand the time frames when IBM believes these use cases are possible, so they have classified each of these use cases into approximate time horizons categories. Horizon 1 would represent those use cases that are expected to become possible using a NISQ level machine within the next few years. Horizon 2 includes use cases that will require larger machines that have a greater number of higher quality qubits, but are still not error corrected. And Horizon 3 includes use cases that are not expected to become possible until more powerful, fault tolerant quantum computers are available in 15 or more years. (Note that these classifications are always subject to change depending upon unexpected breakthroughs or challenges that occur during the development process.)

We hope this provides our readers with a better understanding of how quantum computing will be applied in the next decade or two. The implementation of new use cases will occur gradually and, as we noted in other articles on this web site, we expect the impact of quantum computing to be subtle for the typical end user. The technology will be leveraged by enterprises to either improve the quality or lower the cost of goods and services that a typical person might use. The impact will be subtle, and in many cases, the average consumer may not even realize that they were an indirect beneficiary of the use of quantum computing technology.