# The state of quantum computing: future, present, past

Today is World Quantum Day. It is celebrated on April 14, referring to 4.14, the first rounded digits of Planck’s constant which describes the behavior of particles and waves at the atomic scale, including the particle aspect of light.

World Quantum Day is a bottom-up initiative of a global network of scientists, engineers, educators, communicators, entrepreneurs, technologists and their institutions. Its main objective is to promote public understanding of what could be the next great revolution in scientific research and its applications.

Just like other next big things, the promise of quantum computing, communications and sensing is generating venture capital funds, government involvement, R&D investments from large corporations and many startups. Here’s a quick look at where it’s going, where it is today, and how we got here.

**The future of all things quantum **

Five quantum system developers have announced plans to have fault-tolerant quantum computing hardware by 2030 and many industry observers predict we will see a clear quantum advantage for a number of applications by then. such as drug discovery.

To get an idea of the quantum situation in the near future, I have over the past few days conducted a survey of a number of experts, asking them for their predictions regarding the most significant quantum advance in the past five coming years. Here are the results:

Dr. Celia Merzbacher, Executive Director, The Quantum Economic Development Consortium (QED-C): “There are many areas where progress will be needed and made in quantum computing. I think one of them will be particularly important in quantum error correction, which is essential for realizing the full potential of quantum computing.

Doug Finke, Editor-in-Chief, Quantum Computing Report: “The next five years of quantum computing will be the era of NISQ [Noisy Intermediate-Scale Quantum] machine and we will see more and more powerful NISQ machines being introduced. Although a few applications may use them to gain a quantum advantage, most potential quantum applications will still not find these NISQ machines powerful enough to outperform classical computing solutions. However, by the end of the five-year period, we will begin to see the emergence of error-corrected, fault-tolerant quantum processors and this will be the inflection point for large-scale quantum computing adoption. in real world applications.

David Awschalom, Liew Family Professor of Molecular Engineering and Physics at the University of Chicago, Principal Investigator at Argonne National Laboratory, Director of the Chicago Quantum Exchange, and Director of Q-NEXT, a Center for Quantum Information Science from the Department of Energy: “Within the next five years, we anticipate the emergence of metro-scale entangled quantum networks for secure communication. These networks can also be used to create small clusters of quantum machines for advanced computing. We also believe that quantum sensors will be used to greatly improve intracellular clocks, mapping and sensing.”

Itamar Sivan, co-founder and CEO of Quantum Machines: “I think the most important advancement in quantum computing over the next five years will be the availability of quantum accelerators that can be used as easily as GPUs can. are today. Increasing availability will lower the bar for accessibility, take quantum computing from niche to mainstream, and enable applications to easily benefit from quantum technologies, including improving financial modeling, dramatically improving computational chemistry, and Moreover.

Nir Minerbi, Co-Founder and CEO, Classiq Technologies: “The most significant advancement in quantum computing by 2027 is probably beyond our imagination. In the 1970s, if you asked someone what it was possible to do with billions of transistors on a chip, the answer would probably be “a powerful calculator”, not “using a Google search” or ” Internet in your pocket”. While the most important outcome of the quantum paradigm shift in computing is still unknown or perhaps not even invented, if we are able to ensure that quantum software progresses hand-in-hand with hardware, then by 2027, we will have an incredibly powerful quantum system of computers that would revolutionize materials science, carbon capture, supply chain optimization, and therapeutic discovery. This is one of the reasons why I am so happy to be part of this industry today.

**The state of quantum today**

Funding for quantum research comes largely from the public sector. China has announced plans to invest $15 billion in quantum computing, the European Union $7.2 billion, the United States $1.3 billion, the United Kingdom $1.2 billion. dollars and India and Japan $1 billion each.

The private sector is increasingly engaged. Investments in quantum computing startups topped $1.7 billion in 2021, more than double the amount raised in 2020, according to McKinsey. The number of software-only startups is growing faster than any other quantum computing market segment.

A recent Capgemini survey of business leaders found that 23% of them work with quantum technologies or plan to do so. One in ten expect quantum computing to be available for use in at least one major application within three years. 28% of companies surveyed by quantum software startup Zapata said they have allocated a budget of $1 million or more for quantum investments. 69% of companies surveyed say they have adopted or plan to adopt quantum computing within the next year. Companies adopting Quantum are preparing on several fronts: 51% are identifying talent/building an internal team; 49% are experimenting and building proofs of concept; 48% conduct experiments on quantum hardware or simulators; and 46% create new applications.

**Quantum Mechanics Milestones**

41 years ago, Nobel laureate Richard Feynman claimed that “nature is not classical, damn it, and if you want to do a simulation of nature, you better do quantum mechanics of it”, a statement later seen as a rallying cry. to develop a quantum computer. Here are (somewhat randomly) major milestones in the history of quantum mechanics.

1900 German theoretical physicist Max Planck suggests that radiant energy is emitted, not continuously, but rather in discrete packets called quanta.

1905 Albert Einstein extends Planck’s hypothesis to explain the photoelectric effect – light shining on certain materials can work to release electrons from the material – and suggests that light itself consists of individual quantum particles or photons.

1924 The term quantum mechanics is used for the first time in an article by Max Born.

1925 Werner Heisenberg, Max Born and Pascual Jordan formulate matrix mechanics, the first conceptually self-contained and logically consistent formulation of quantum mechanics.

1930 Paul Dirac publishes *The principles of quantum mechanics*a textbook that became a standard reference work still used today.

1935 Albert Einstein, Boris Podolsky, and Nathan Rosen publish an article pointing out the counterintuitive nature of quantum superpositions and claiming that the description of physical reality provided by quantum mechanics is incomplete.

1935 Erwin Schrödinger, discussing quantum superposition with Albert Einstein, develops a thought experiment in which a cat (still known as Schrödinger’s cat) is simultaneously dead and alive; Schrödinger also coined the term “quantum entanglement”.

1947 In a letter to Max Born, Albert Einstein first refers to quantum entanglement as “frightening action at a distance”.

1951 Felix Bloch and Edward Mills Purcell receive a shared Nobel Prize in Physics for their first observations of the quantum phenomenon of nuclear magnetic resonance.

1963 Eugene P. Wigner lays the foundation for the theory of symmetries in quantum mechanics as well as fundamental research on the structure of the atomic nucleus.

1976 Roman Stanisław Ingarden publishes one of the first attempts to create a theory of quantum information.

1980 Paul Benioff publishes a paper describing a quantum mechanical model of a Turing machine or classical computer, the first to demonstrate the possibility of quantum computing.

1985 David Deutsch of the University of Oxford formulates a description of a quantum Turing machine.

1993 The first article^{ }describing the idea of quantum teleportation is published.

1994 Peter Shor develops a quantum algorithm for integer factorization that has the potential to decrypt RSA encrypted communications, a widely used method for securing data transmissions.

1996 Lov Grover invents the quantum database search algorithm.

1998 First demonstration of quantum error correction; first evidence that a certain subclass of quantum computations can be effectively emulated with classical computers.

2004 First five-photon entanglement demonstrated by Jian-Wei Pan’s group at the University of Science and Technology of China.

2014 Physicists at the Delft University of Technology in the Netherlands teleport information between two quantum bits about 10 feet apart with a zero percent error rate.

2017 Chinese researchers report the first quantum teleportation of independent single-photon qubits from a ground-based observatory to a satellite in low Earth orbit with a distance of up to 1400 km.

2021 Researchers at the University of Chicago send, for the first time, entangled qubit states via a communications cable connecting a quantum network node to a second node.