Quantum Computing is an enormously active scientific-technical discipline, if one takes into account the number of researchers and engineers working in the area, the international investment being dedicated to its development and the media interest it arouses in the media.

The number of researchers working on Quantum Computing is growing rapidly, since the explosion of the area following the work of P. W. Shor on polynomial factorization of integers, presented in 1994. Proof of this is the growth in the publication of scientific articles on quantum technologies. which, in 2010, was about 800 articles per year and in 2018 more than 5,000, according to a Quantum Reports study.

The Quantum Computing market size exceeded $500 million in 2020 and will surpass $28 billion by 2028, growing more than 30% annually from 2021 to 2028, according to a study by Global Market Insights.

Quantum Computing appears in the media very frequently. Thus, so far, more than 450,000 news items have been published on the subject, according to data obtained by the Google search engine. It could be said that there is an information fever about this discipline and particularly about its expectations for the future. However, in the words of Physics Novice Serge Haroche “We shouldn’t exaggerate the advances in quantum computing, there’s a lot of hype about it”.

The irruption of companies and start-ups in Quantum Computing has been the trigger for the commented media attention. Among the most important are IBM, Google, Microsoft, Intel, D-Wave, Rigetti Computing, Fujitsu, Xanadu, Origin Quantum Computing Technology, Ion Q, etc. The following table shows some of the most prominent quantum gate processors, both currently available and planned for the next few years.

Company | Qubits | Name | Year |

IBM | 65 127 433 1.121 4000+ | Hummingbird Eagle Osprey Condor Kookaburra | 2021 2021 2022 2023 2024 |

53 | Sycamore | 2019 | |

Rigetti Computing | 40 80 84 336 | Aspen-11 Aspen-M-2 Ankaa Lyra | 2021 2022 2023 2023 |

Xanadu | 216 | Borealis | 2022 |

Origin Quantum | 24 | SC24A | 2021 |

Ion Q | 23 | Aria | 2022 |

Quantum Computing is often presented as some kind of magical technology that will solve many of the problems that classical computers cannot solve in a reasonable amount of time. In the words of Seth Lloyd “A classical computation is like a solo voice – a line of pure tones that follow one another. A quantum computation is like a symphony – many lines of tones interfering with each other.” Along these lines, and as an example, in an Intersog article we read the following:

So the expectations are sky high. From solving highly complex mathematical problems in a blink of an eye to building un-hackable global networks, experts expect quantum computing to define global information technology for decades to come.

We are currently in the embryonic stage of the fourth industrial revolution, but once these machines realize “the dream,” you can expect it to usher in an accelerated period innovation and transformation that will be known as the Quantum Age.

Quantum Computing: Expectations vs. Reality – 10 de septiembre de 2018

However, almost thirty years after the publication of P. W. Shor’s work, the two key questions about Quantum Computing remain unanswered:

- Is Quantum Computing more powerful than Classical?

- Is efficient control of quantum errors possible?

Regarding the first question, Google claimed in 2019 that it had demonstrated quantum supremacy. However, later works disproved this statement by solving the problem proposed by Google in classical computers. As for the second, the “quantum threshold theorem” would imply that the answer is affirmative. However, the discrete quantum error model used in the proof of this theorem does not seem to be sufficient to model the real errors of quantum computers, as shown for example in the following article: Quantum codes do not fix qubit independent errors.

We could say that, today, there are many expectations about Quantum Computing but very few certainties. In the Quantum Explore project we want to address the present and future of Quantum Computing from scientific rigor, without getting carried away by the media euphoria about the expectations of this discipline. If you are interested in this approach, we invite you to register to be able to find out about the activities linked to this project.