US – Quantum computers can solve – in theory – complex problems much more efficient and faster than the best currently available super computer. Now American physicist developed a quantum simulator in which 219 beryllium ions were coupled together as a precursor for such a quantum computer. This condition is also called entanglement. With this experiment, the scientists, in their work published in the journal Science, raised a new record for the number of data units for quantum computers i.e. qubits.

“We could clearly demonstrate that all ions were entangled with each other”, says Justin Bohnet from the National Institute of standards and technology (NIST) in Boulder. Together with his colleagues, he started 219 beryllium ions in a penning trap. The frozen ion was exposed to a strong magnetic field of 4.5 Tesla. The spin of the ions was over in a special quantum state, which is called superposition. The spin of the ions was both upwards and downwards at the same time.

First, all ions independently showed the quantum state of superposition. However, the ions settled with the use of precisely tuned microwaves together with quantum link, say interlock. Thanks to the superposition and the entanglement, qubit could be used in future in the calculation of complex problems.

As evidence of the successful interweaving, Bohnet and colleagues determined the orientation of the  ion spins with a laser. The ions lost the quantum state of superposition and reacted with the emission of fluorescent light. This measurement showed only a very weak noise. In line with theoretical predictions by the researchers, this suggested a clear evidence of the previously presented entanglement of 219 ions. The noise would have been significantly more potent without entanglement.

With this basis experiment showed by Bohnet and colleagues, hundreds of ions can be arranged to entangle qubits and can be controlled. Thus, ions are recommended as hardware for the future development of quantum computers. Quantum coupled ion could provide new impetus for other areas of research. Bohnet concluded that with the reduction of quantum noise this way, the entanglement could also be useful for improved atomic clocks.