Quantum computers with immense computing power and a secure and impenetrable quantum internet. It might seem like the introduction to a science fiction novel, where quanta rewrite the computer universe.
Instead, in 2024, they become a possible and ever closer future.
On the one hand, an ultrapure silicon chip accelerates the race to build quantum computers, thanks to the discovery of researchers from the universities of Manchester and Melbourne led by Richard Curry and David N. Jamieson, and published in Communications Materials.
On the other hand, the first concrete supersecure transmission of the quantum internet. Researchers from Harvard University, led by Mikhail Lukin, transmitted data in the form of light particles through the traditional fiber optic network at a distance of 50 kilometers.
But to understand the importance of the ongoing information revolution we need to take a step back.
In the beginning, it was bits. Fundamental units of information that make up the computer chips we use every day, just like the one I'm writing from, and that speak binary code. Long sequences of 0s and 1s, which are reeled off, transmitting information. Since the first PCs, we have witnessed a rapid evolution: increasingly powerful chips, computers capable of carrying out complex calculations more quickly. And the internet, where bits travel along the cables carrying information elsewhere, always with the risk of being intercepted and revealed, if not appropriately encrypted and protected.
However, quantum mechanics has arrived to rewrite the rules. Imagine a fundamental unit of quantum information, which is not limited to binary code, but introduces complexity. States are no longer just 0 and 1, black or white, but can exist in a superposition state at the same time. Imagine, then, an internet where information travels through particles of light and communicate using entanglement, a sort of instantaneous connection between atoms. Due to this physical property, particles communicate with each other even at great distances, without anyone being able to intercept and decipher their messages.
From the first intuition, quantum bits, or qubits, are born, the bricks at the basis of the construction of future, but no longer so distant, quantum computers. An electron or an atom which, immersed in a magnetic field and isolated from the external environment, manages to process the inputs it receives at the same time, exponentially increasing the computing power of the machine.
Since then, researchers have been trying to find the Holy Grail of quantum computing: a material that allows them to create chips that can host qubits and allow them to work at full power.
To date, various technologies are being tested, all still in the embryonic stage of development, to spread the power of quantum computing. The main difference between different quantum computer prototypes is based on the technology used to make the qubits, but they follow a common goal: keeping the qubits isolated from the environment. Temperature, vibration and even the slightest electromagnetic field affects the superposition state of qubits, making them unusable.
For example, superconducting qubit quantum computers are stable and allow complex calculations, but in order to work the qubits must be at temperatures close to absolute zero (-273.15 °C), requiring massive and expensive cooling systems. This is why they are found in research centers and universities.
Quantum dot qubit computers, on the other hand, use chips to create quantum dots in a semiconductor, so that the qubit is isolated enough to ensure consistency in calculations and stability. A huge advantage because they could be made on a large scale with production techniques that are similar to those of classical electronics and also work at room temperature.
From entanglement, however, the quantum internet is born. The transmission of digital data packets uses the classic fiber optic network so that entangled qubits exchange information over large distances, just as if they were close together. A real and reproducible result, like the one achieved for the first time by Harvard researchers. As with quantum PCs, the challenge is to create stable qubits that can maintain state and transport data packets for a defined time.
A quantum computer would be able to carry out complex calculations very quickly, leading to the discovery of new molecules, which would find application both in the development of drugs and innovative materials. They would be a threat and a salvation: capable of deciphering current encryption systems in a short time, with concrete risks for IT security at any level, but laying the foundations for the development of new and even more indecipherable cryptographic systems.
And last but not least, there is artificial intelligence. OperAI's ChatGPT and Google's Gemini represent an industrial revolution that has spread rapidly throughout the world and which already appears unstoppable. Intelligent algorithms find solutions quickly, pose new problems but represent the wave of innovation that cannot be stopped.
Imagine, therefore, a ChatGPT or a quantum Gemini: unlimited computing power for an algorithm already capable of revolutionizing. Cross and delight of the challenge to an artificial intelligence which, if quantum, would have no difficulty in wanting from a simple algorithm executor of instructions to be able to become almost human.
And imagine a quantum internet that brings unlimited information, in a short time and in a completely safe and indecipherable way.
There are, therefore, no shortage of limits. Making stable qubits is a real challenge. A challenge made up of many small battles won so far, where step by step we open up to the power of quantum computers and the quantum internet.
Here we find ourselves at a crucial crossroads. Quantum computers are a reality, although still limited and unstable. The first super-secure transmission between particles of light, however, demonstrates that we are on the right path to the network revolution.
The road ahead to create stable qubits to guarantee computing power and transmission capacity currently belongs only to this realm of dirty silicon and fiber optics.
With these new discoveries, however, we find ourselves in a future that has the flavor of an almost reality towards consumer quantum computing, between ultra-pure silicon and particles of light that show the way.