The quantum world makes us think of a science fiction movie where the application of this scientific field is only used in Antman, Doctor Strange or Avengers. Yet, quantum computing is no longer a futuristic concept. The world has entered the quantum decade, where companies are beginning to see the commercial value of quantum computing. This concept could then be central to the global economy in 2050.
In 2019, Google, thanks to their brand new quantum computer, announced that they had solved a problem in just 3 minutes, while a classic computer would have taken 10,000 years. It is the “quantum supremacy” that is being witnessed when the quantum computer overtakes the classical computer. However, IBM showed that this calculation could be done in 2 days by a conventional computer. Quantum supremacy was therefore not achieved in 2019.
In a classical computer, all calculations are done with bits, with 0s and 1s.
The quantum computer uses Qbits which are both 0s of 1s and all values in between. This is possible, thanks to the properties of quantum physics, studying the infinitely small. A particle can be in several places at the same time and in several states at the same time. It is the superposition of states. For example, the electron has a characteristic called SPIN. In quantum, the state of an electron is not just spin up or spin down, it is the superposition of the 2. The 2 states of the particle coexist each time a probability is associated with them.
An example of what quantum computers can do when users are looking for music on Apple Music :
Music has a bit code, with 0 and 1. The classic computer will compare the code of our search with all the codes in the database one by one, so it takes time. The quantum computer, for its part, analyzes in Qbit so the states 0 and 1 are superimposed, it can take all the codes at once and compare them at once. The search time is therefore much faster. However, this concept is not only used to search algorithms, but also for ultra-complex calculations.
Thanks to quantum teleportation, if we change the property of a single particle, we can change the property of another particle even if it is thousands of kilometers away. This could open the way to the quantum internet.
The major obstacle to the quantum computer? It can make miscalculations because the particle inside each Qbit is extremely sensitive to its environment. A simplification of the magnetic field into the electric field, or even radiation from a nearby hot object, may be enough to alter the Qbit. This is called decoherence. Today, the priority of scientists is rather to limit the kind of calculation with the least possible of Qbit. They can do that by improving the precision in the engineering of the Qbit, or by creating algorithms for the correction of calculation errors.
According to estimates? A quantum computer of 300 Qbits, without calculation error, would be able to simulate all the physical laws of the universe from the Big Bang until today – which is huge.
With an estimated global market of $948.82 million by 2025, quantum computing promises countries that win this global technological competition a considerable commercial and military advantage.
Where is France’s place in all this?
On January 21, 2021, Emmanuel Macron unveiled a national strategy on quantum technologies. Based on the principles of quantum physics, the latter are attracting the interest of several countries. In addition to the progress of other countries in quantum technologies, France must also face Chinese and American competitors, who have greater means. This is why it also seeks to make Europe a leader in this field, by multiplying collaborations. France notably aims to be among the first nations to develop a large-scale universal quantum computer. She hopes to have “a complete prototype of a first-generation general-purpose quantum computer” by 2023 and planning an investment of 1.8 billion euros.
In 2022, France will continue its efforts within the framework of its quantum plan. In the coming months, the government plans, for example, to launch a call for projects for post-quantum cryptography, a branch of cryptography consisting in developing algorithms that allow quantum computers to resist attacks. With the development of IT in this area, it is becoming necessary to be able to guarantee data security.