#### In this article we will explain what are the features of the quantum computer, all the possible applications and how it works. Find out more.

Quantum computers are one of the most interesting innovations of recent years: faster, more efficient and functional devices that exploit the combination of quantum physics and computer science to solve very complex problems in a short time. Specifically, the curiosity for these super technological devices is growing rapidly following the presentation of Sycamore, Google's quantum computer that, in an experiment coordinated by Google and conducted by NASA, Caltech (California Institute of Technology) and the Technical University of Aachen (Aachen, Germany), has solved in just over 3 minutes an operation for which a traditional computer would have taken about 10.

To date, the world of quantum computing is rapidly evolving but many of its aspects, especially with regard to its possible applications, are still under discussion and, in fact, still difficult to understand for non-experts. Let's try to understand what is a quantum computer, how it works and what can be its practical applications.

#### What is a quantum computer and how it works

The quantum computer is a device with a data processing capacity and a computing power far greater than that of any other classical computer: in the latter, in fact, some "physical" aspects, such as the hardware architecture used, limit the complexity of the solvable problems.

The quantum computer, however, exploits the laws of physics and quantum mechanics by replacing the "classic" bit, the minimum unit of information of a conventional processor, with the qubit (quantum bit), subatomic particles such as photons or electrons capable of storing much more information.

In fact, while the digital bit is a binary entity that can assume the values 0 and 1 depending on the passage or not of current, the qubit can represent both states at the same time (both 0 and 1), which can also influence each other even if not physically connected; the qubit is therefore a fundamental unit capable of performing calculations simultaneously thanks to the superposition of quantum states.

#### The possible applications of the quantum computer

As already said, the quantum computer is able to process at the same time several solutions to a single problem through parallel computing; and, if it is true that today most of the possibilities of these devices are still to be discovered, it is also true that researchers are trying to identify the most interesting practical aspects to design and implement in real life.

For example, the Volkswagen Group has started, in collaboration with Google, a pilot project for the real-time optimization of traffic flows, exploiting the power of Google's quantum computers. At the same time, quantum computing could be effectively used at a practical level in cryptography (cybersecurity), in weather forecasting and in the realization of new materials.

Despite the results achieved in the field of quantum computing, it is still too early to imagine all the possible applications of quantum computers; the same Sycamore, Google's quantum computer, has solved a mathematical problem of purely academic interest, without any practical implications. So, we just have to wait, continuing to follow the research and the work of professionals who will make (sooner or later) quantum computers a practical reality.

#### Quantum computer Quby

It has been recently presented Quby, the quantum computer built by the startup Active Cypher able to reduce the time to conduct a brute force attack, even in the case of cryptographic algorithms such as AES-256. Quby (whose name is derived from qubit) is capable of cracking any type of access credential stored in encrypted form in seconds using open quantum algorithms.

Mike Quinn, Chief Strategy Officer at Active Cypher, said that "the power of Quby exposes the inherent vulnerabilities of most IT security infrastructures. The benefits of quantum computing will undoubtedly be numerous (...) but it would be reckless not to realize the dangers that such a technology can introduce should it fall into the hands of malicious parties."

#### Quantum Computers and Artificial Intelligence

Quantum computers may be able to solve very complex tasks, far beyond the capabilities of traditional supercomputers, but quantum states are extremely sensitive to interference coming from the external environment, such as vibration and temperature.

To protect quantum computers from this problem, a number of complex error-correction strategies have been devised. Among them, the work of Florian Marquardt, director of the Max Planck Institute for the Science of Light, and his team is particularly fascinating.

This system is based on the capabilities of artificial neural networks, programs that can mimic the interconnected behavior of neurons in the human brain, and the possibility that, with sufficient training, these networks can learn a fundamental task for the future of quantum computers, quantum error correction, effectively outperforming other quantum error correction strategies.