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Controversial Quantum Computer Beats Factoring Record

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quantum illustration

Quantum computers will be able to conduct far more complex calculations than possible with today's most advanced supercomputers.

Credit: Berkeley Lab

Chinese researchers recently used a process called adiabatic computing to find the prime factors of the number 143, beating the previous record for a quantum computer of 21. However, some quantum computing experts doubt that this method is actually the result of a quantum system.

The Chinese experiment is based on liquid-phase NMR technology, which involves spins of hydrogen nuclei in molecules of 1-bromo-2-chlorobenzene. Each spin is a quantum magnet that can be manipulated using bursts of radio waves.

Adiabatic quantum computing does not use the circuits and separate components found in other quantum and classical computers, which are based on switches and logic gates. Instead, an adiabatic quantum computing system encourages qubits to find the answer collectively. The method relies on a pool of qubits always seeking its lowest overall energy state.

The Chinese computer has just four qubits, and it is difficult to scale up liquid-phase NMR further, which means different hardware would be required to factorize larger numbers. However, "the algorithm could be used in other quantum-computing architectures," says University of Science and Technology researcher Jiangfeng Du.

From New Scientist 
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