Physicists use ‘hyperchaos’ to model complex quantum systems at a fraction of the computing power

Physicists have discovered a potentially game-changing feature of quantum bit behavior that enables scientists to simulate complex quantum systems without requiring enormous computing power.

The development of next-generation quantum computers has been limited for some time by the processing speed of conventional CPUs. Even the world’s fastest supercomputers have not yet been powerful enough, and existing quantum computers are still too small to model moderate-sized quantum structures, such as quantum processors.

However, a team of researchers from the universities of Loughborough and Nottingham and Innopolis have now found a way to circumvent the need for such large amounts of power by employing the chaotic behavior of qubits – the smallest unit of digital information.

In modeling the behavior of quantum bits (qubits), they found that when an external energy source, such as a laser or microwave signal, was used, the system became more chaotic, eventually showing the phenomenon known as hyperchoism.

When the power supply was excited about the power supply, they switched from status, like ordinary computer bits moving between zero and one, but in a much more irregular and unpredictable way. However, the researchers found that the degree of complexity (hyperchaos) did not increase exponentially as the size of the system grew – this is what one would expect – but instead it remained proportional to the number of units.

In a new paper, “Emergence and control of complex behaviors in driven systems of interacting qubits with dissipation”, published in the Nature journal NPJ quantum information, the team shows that this phenomenon has great potential to allow scientists to simulate large quantum systems.

One of the corresponding authors, dr. Alexandre Zagoskin, from Loughborough’s School of Science, said: “A good analogy is aircraft design. To design an aircraft, it is necessary to solve certain equations of hydro (aero) dynamics, very difficult to solve and became possible only after the Second World War, when powerful computers appeared, nevertheless humans had long ago designed and flown aircraft, this was because the behavior of the airflow could be characterized by a limited number of parameters, such as the Reynolds number and the Mach number, which could be determined from small-scale model experiments, without which direct simulation of a quantum system in all details, using a classical computer, becomes impossible once it contains more than a few thousand cubic meters, there is not enough matter in the Universe to build a classic computer that can handle the problem.If we can characterize different regimes of a 10,000 kwbit quantum computer by just 10,000 such parameters instead of 2^{10 000} – which is about 2 times 1 with three thousand zeros – that would be a real breakthrough. ‘

The new results show that a quantum system shows qualitatively different patterns of general business behavior, and the transitions between them are controlled by a relatively small number of parameters.

If applicable, the researchers can determine the critical values ​​of these parameters, for example to build and test scale models, and by taking some measurements of the actual system, to determine whether the parameters of our quantum processor allow it to be correct. work or not.

As a bonus, the controllable complexity in the behavior of large quantum systems offers new possibilities in the development of new quantum cryptography tools.