By Olumayokun Aikomo.
Quantum supremacy. The phrase which has been coined by Professor John Preskill in 2012, is used to describe the point at which computers can do things that classical computers cannot. These are not just extremely complicated problems that require equally complicated computations but can be extended to computational tasks that are simple and are not required to be useful.
The way that quantum computers differ from normal ones can be explained by the way that both computer types receive, write and send information. Normal computers operate with information in binary states. These states are either a 0 or 1 and are known as bits. This means that information is only ever be one or the other. Quantum computers, on the other hand operate with information in (quantum physics and therefore with) quantum bits – also known as qubits. Rather than being one or the other, a qubit is not limited to one state and can be both a 0 and a 1 at the same time. Hence, it has a greater range of use within computing. With qubits, quantum computers can work on a million computations at once whilst a normal desktop PC works on one.
Recently, a Google paper to be published in the journal Nature was leaked through the error of the National Aeronautics and Space Administration (NASA). The paper includes claims of Google finally being able to develop a quantum computer. They used their own design, Sycamore, of a quantum processor, to create the quantum computer that has performed a computational task near impossible for a conventional computer to complete.
The task in question (sampling the output of randomly chosen quantum circuits) is alleged to have been completed in 200 seconds by Google’s quantum computer. In comparison, Google alleges that this same task would require 10,000 years for the world’s most powerful supercomputer, Summit, to complete. This alone should display the technological prowess of Google’s own quantum computer over any other type of computer, right?
IBM has some challenges with regards to the information within Google’s published paper, however. They do not disagree with the importance of the achievement of Google and they knew avenues that the research may lead to, but claim that their own simulations on the world’s most powerful supercomputer have led to the completion of the same task as Google’s quantum computer in two-and-a-half-days instead of 10,00 years. The IBM paper that details the results of their own simulations sheds light on how they went about with their research; they found a way of making a trade-off between increased memory usage and faster computation time and how through this, the results of the simulations carried out by Google could be carried out through their own algorithm without the use of a quantum computer.
Though it is a huge step and accomplishment in the name of technology, many argue that the use of the term “supremacy” alludes to quantum computing being able to carry out more than is possible. Though they can outperform normal computers in some tasks, they do not outperform them in all tasks. The method used to demonstrate the practicality of quantum computers; random circuit sampling also has no practical applications to anything significant. The method does give way to the reasoning behind the belief that quantum computers can demonstrate higher abilities than traditional ones and it cannot give provision to reasoning behind anything else.
Many may argue against the term quantum supremacy and how it may lead to misinterpretation, but Google are not arguing that quantum computers are more than what they are or that they can do more than what is already known. Neither do they allude to quantum computers being able to make immediate changes to the way that computing is already carried out. Google’s team have simply added a significant piece of research to what is already known within the large community of technology – still acquiring and deepening its understanding and knowledge on the topic of quantum computing.
Along with many other accomplishments, it may become clearer as to what quantum computing can do for the world of technology. The experiment is not quite just another drop in the ocean of research, but it is not exactly the cause of a wave of new information.