We have always heard of the usefulness of a quantum computer as a prophecy of a distant future. But this week, IBM scientists released the results of a study that brings us a little closer to that future.
The research published this week in the journal Nature (I link it to you here) compares a "classic" supercomputer and a quantum computer of over 100 qubits, to evaluate the latter's usefulness.
The "fighting ground"? The simulation of physical laws.
Like an artist sculpting clay, one of the first tasks that show the usefulness of quantum computers may be to model components of materials that classical computers have never been able to effectively simulate.
This would have huge potential impacts, from creating more efficient fertilizers to designing better batteries, not to mention breakthroughs in medicine.
Recap: what makes a quantum computer so special?
Well, while a classical computer reads "binary" information as a number zero or a number one, the quantum computer can read both at the same time. This theoretically makes it much more effective at solving certain problems, such as searching an unordered database… or simulating natural phenomena.
Of course, creating a quantum computer that has a utility is no cakewalk. Qubits, quantum equivalents of classical bits, are very sensitive to noise and interference from the surrounding environment, which can create errors in calculations. And as quantum processors get bigger, these errors can also accumulate. How to overcome them?
The study to give utility to the quantum computer
IBM researchers worked with a 127-qubit Eagle quantum processor to model the spin dynamics of a material, predicting properties such as its response to magnetic fields. They have generated large, intertwined states, where certain simulated atoms are correlated with each other. And thanks to a technique called "zero noise extrapolation", they were able to separate the noise and get the true response.
To make sure that the answers obtained from the quantum computer had utility and were reliable, another team of UC Berkeley scientists ran the same simulations on a set of classical computers and got matching results.
The (future) utility of quantum computing
While classical computers have an upper limit for these kinds of problems, especially as the models get more complex, the IBM quantum processor is still striving for quantum supremacy. But having demonstrated that it can provide useful answers even in the presence of "noise" is a remarkable achievement.
"What we have observed is unprecedented: Quantum computers have succeeded in accurately modeling a natural physical system in a more advanced way than classical methods," he said. Dario Gil, senior vice president and director of IBM Research. 'This milestone represents an important step in demonstrating that current quantum computers are valid scientific tools, capable of tackling extremely difficult problems, possibly impossible for classical systems. We are now entering a new era of utility for quantum computing.'
What are you saying? You are right?