Scientists have confirmed: quantum computer does what a normal computer can never do

An international team of researchers led by scientists from the University of Texas at Austin has for the first time presented experimental evidence that a quantum computer can solve problems unattainable for classical systems.

The results have been published on the arXiv preprint server and have already been hailed as the biggest step towards the practical application of quantum supremacy.

The main difference between quantum machines is the use of qubits instead of traditional bits. Whereas a classical bit can only be in a "0" or "1" state, a qubit is capable of being in superposition, combining both values. This opens up access to exponentially more memory and processing power. However, until now there has been no rigorous proof that this potential can be realistically realised.

The "Alice and Bob" challenge
To demonstrate quantum superiority, scientists developed a mathematical problem that simulated a game between two parts of the quantum system - the notional "Alice" and "Bob". Alice had to create a quantum state and transmit it to Bob, and Bob had to measure it and determine the result before Alice had even completed the preparation.

The experiment was repeated more than 10,000 times, optimising the process. The analysis showed that a classical computer would require at least 62 bits of memory to perform the task with similar accuracy, while the quantum processor managed with only 12 qubits.

Unequivocal proof of superiority
Previously, many claims of quantum superiority were based on assumptions that classical algorithms would not be able to catch up with quantum algorithms in terms of efficiency. However, a new study has for the first time provided unconditional mathematical proof that no classical algorithm can perform a task as efficiently as a quantum computer.

"Our results show that modern quantum processors can generate and manage entangled states of sufficient complexity to take advantage of the exponential capabilities of quantum memory," say the paper's authors.

What this means for the future
The move paves the way for practical applications of quantum technology. Among the potential areas:

• Cryptography - creating more secure data exchange systems.

• Pharmaceuticals - accelerating molecular modelling and developing new drugs.

• Materials science - finding and testing new materials with unique properties.

Quantum computers can not only solve problems faster, but also work with such arrays of information, which are simply unattainable for classical machines.