Technology enthusiasts will not have missed the news of a few days ago, never denied or officially confirmed: Sycamore, Google’s quantum computer, would have succeeded in achieving the so-called quantum supremacy: carrying out, for the first time in the world, a series of operations that traditional computers would take tens of thousands of years to do… and did it in minutes!
In detail, Sycamore would have succeeded in demonstrating that a sequence of random numbers is really random (a mathematically very complex problem) in about three minutes and twenty seconds; Summit, the most powerful traditional supercomputer in the world, would take about 10 thousand years.
NASA’s mysterious article
On the NASA website, an article entitled “Quantum supremacy using a programmable superconducting processor” appeared. The paper remained online for a few hours and then removed, but it was enough for someone to save it, divulge it and generate controversial comments, assumptions and hopes among the experts.
What is a quantum computer?
The basics of computer science teach us that the minimum unit of information of a conventional processor is the bit, a binary entity that can assume the values zero or one depending on the passage of current. Thus, traditional processors admit only two states, linked to the passage or non-passage of current, that is, a flow of electrons.
Instead, quantum processors use qubits, subatomic particles like photons or electrons, which instead can store and carry much more information, greatly amplifying computing power compared to that of a classic computer (and supercomputer).
Why are subatomic particles “faster” in calculations?
The laws of quantum mechanics explain that each particle is subject to the so-called superposition principle, ie that it can be found simultaneously, with different probabilities, in several different states.
Tommaso Calarco, director of the Jara-Institute Quantum Information and chairman of the European Quantum Flagship Network tells: “The superposition principle allows to overcome the on/off dualism and to convey much more information: a quantum particle can simultaneously represent more states”. The qubit, therefore, allows many operations to be performed simultaneously, parallelizing the calculations.
Will a new personal computer arrive soon?
This doesn’t mean that we will all have a quantum computer in the near future. The “old” processor will remain for a long time the solution with the most suitable cost/benefit ratio for all uses, personal or business. But, in sectors like materials science, pharmaceutical industry, particle physics, a quantum processor could really make it possible to make technological advances of vast scope and difficult to predict now!
Just a few days before the Google leak, in fact, IBM had announced that in October it would allow engineers, physicists and computer scientists to remotely access a 53-qubit quantum computer, the largest ever made available for external use. Google, on the other hand, has Sycamore, a 54-qubit computer (one of which does not seem to work as it should, and therefore 53 are used), and another 72-qubit system, which at the moment was too difficult to manage.
The instability of quantum systems
Quantum systems are extremely delicate, and particularly susceptible also to imperceptible thermal and electromagnetic interferences: “To give an idea of the enormous difficulty of managing and controlling quantum computers”, Calarco explains, “we can think of qubits as components of an orchestra called to play Beethoven’s ninth symphony. But each musician must be able to do it with boxing gloves in his hands and a helmet on his head. And in a room kept at ninety degrees of temperature. It’s a very, very difficult task!”, He adds, “It is still far too early to imagine all the applications. They could be really exterminated, and amazing. The next steps are first of all to further improve the hardware, arriving to precisely control systems with 100 or more qubits, and then work on the development of algorithms that allow us to arrive at the quantum advantage”.
Who knows, maybe one day, even thermal management will be controlled by a quantum processor!
News and information taken from Wired.it