Google’s recent article on quantum computing published in the scientific journal, Nature, has been a source of intense debate. The Mountain View company claims to have executed a computational task in 200 seconds (three minutes and 20 seconds). The operation involved performing a random sampling calculation, which would have taken the world’s most powerful supercomputer 10,000 years. This would be the first empirical demonstration of quantum supremacy, a term that describes the point where quantum computers have an unparalleled advantage over classical computers — when they can perform a task that classical computers cannot.
Shortly after Google’s announcement, IBM countered the claim: “Big blue” believes that a supercomputer based on classical computing could run the same experiment in just two and a half days. Both companies are the leading contenders in the race to successfully develop this technology and are independently responsible for the greatest advances made to date.
Samuel Fernández Lorenzo, who works with BBVA’s New Digital Business (NDB) leading research into quantum algorithms, pointed out that the term “quantum supremacy” lends itself to misinterpretation outside technical fields: “It was a term coined by a professor at the California Institute of Technology, John Preskill, to refer to the time when we would be able to build a quantum processor that would be capable of performing a particular task that a classic computer could not execute in a reasonable amount of time.” He stresses that, even if this event has been achieved, it does not come close to implying that a quantum computer is more appropriate or otherwise better to use for any task than a traditional computer.
The computer built by Google, with 53 operating qubits and high processing speed, can execute one specific task. In fact, quantum computers available to researchers today only serve to test algorithms for small problems. Juan José García Ripoll, a researcher at the Institute of Fundamental Physics (IFF), part of the Spanish National Research Council (CSIC), explains that the most remarkable problems they address include the simulation of quantum systems, like small molecules; optimization problems; and small machine learning tasks, such as data classification. “These applications are exploratory and depend on the size of the processor, the speed with which we can perform operations, and most of all, the amount of time quantum states persist in the processor, which is still very brief,” he says.
Quantum computing could also have a strong impact on banking. “There are a lot of financial problems related to investment strategy optimization, which involves researching a huge number of possible portfolio combinations to find the one that best fits specific criteria. A quantum computer can help during this exploratory task and provide us with investment options that are better than those calculated by classic methods,” the researcher explains.
This technology can also serve to streamline routine activities such as risk calculation or the valuation of financial products that are based on numerically simulating various financial scenarios. In addition, algorithms are used in numerous finance industry decision-making processes. For example, to recognize fraudulent transactions: “It is not unreasonable to think that quantum computers could be used in the future to speed up these kinds of algorithms and produce better results.”