Quantum Utility, Advantage and Supremacy

- Overview

As the quantum computing industry continues to move forward, so does the goal.

A long-sought goal is to achieve quantum "supremacy" -- proving that quantum computers can solve calculations that classical computers on Earth can't -- without actual benefit.

Google claims to have achieved this goal with a landmark scientific paper published in 2019, but IBM is clearly skeptical. In any case, this is an exercise in computer science and has no practical significance in the real world. 

Since Google's announcement, the industry has stepped up its efforts to gain quantum "advantage," defined as a commercial or scientific advantage achieved by exceeding the computing power of the largest supercomputers in the application in question.

It's certainly more useful than Quantum Supremacy as a reference point for comparison and benchmarking. Quantum supremacy is often associated with major breakthroughs in drug discovery, financial transactions or battery development.

- Quantum Utility vs. Quantum Advantage vs. Quantum Supremacy

Getting quantum computers into use as soon as possible is a much better goal than quantum superiority and quantum supremacy. The ability of a quantum computer to far exceed the capabilities of a classical supercomputer is known as quantum supremacy. A quantum device that can perform a calculation better than a supercomputer at a certain task is called quantum advantage.

However, quantum supremacy misses an important point: should we really wait for a million-qubit quantum steampunk gold chandelier to overtake a supercomputer before thinking quantum computers make sense? Or should we focus on measuring performance improvements compared to hardware units used in today's classical computers, such as individual CPUs (central processing units), GPUs (graphics processing units), and FPGAs (field programmable gate arrays)?

Because for this still nascent industry, the more worthy goal may be to achieve quantum "utility" or usefulness as soon as possible. Quantum utility is defined as a quantum system that outperforms a classical processor of comparable size, weight, and power in a similar environment. 

- Accelerating Quantum Commercialization

Those who have studied quantum computing deeply know that it will have a huge impact on IT, business, economy and society. The future of quantum supercomputing mainframes with exponential acceleration, error-correcting qubits, and a quantum internet will be a very different world than the one we live in today. 

That said, similar to the classic mainframes of the 1960s, quantum mainframes are likely to remain large and fragile machines for the foreseeable future, requiring ultra-low temperatures and complex control systems to operate. Even when fully operational, there will only be a handful of quantum hosts in supercomputing and cloud computing facilities around the world. 

The quantum computing industry would be better off if it mimicked the success of classical computers. When personal computers came out in the late 1970s and early 1980s, IBM and other companies were able to introduce new models each year that offered incremental improvements over previous models. This market dynamic drives the development of Moore's Law. 

Quantum computing needs similar market dynamics to scale and thrive. Investors can't be expected to keep throwing money at them, waiting for quantum computers to overtake a handful of supercomputers. The annual release of new, improved and more "useful" quantum computers will provide the assurance of revenue, driving the long-term investments needed to realize the technology's full potential. 

With a steady stream of useful quantum systems available for a variety of applications, there's no reason to wait in line to handle computations on one of the few large-scale quantum hosts available in the cloud when you can have a quantum processor right next to you. You, integrate with your existing classic systems. Your application may require instant computing that "quantum in the cloud" cannot deliver in time, or you may have to rely on local or on-board computing if cloud access is not available.

<More to come ..>