Russian scientists have come up with a method that appears to make the development of a multipurpose quantum computer much easier. They suggest that multilevel quantum systems be used in the process, in which each level can operate just like a number of ordinary quantum elements we call qubits.

The development team has brought together researchers from MIPT, aka Phystech—a leading Russian technology university based in Moscow—and the government-supported Russian Quantum Center. The scientists are reported to have dropped attempts to preserve stability in a large qubit system—a state critical for quantum computing—and elected to seek methodology of reducing the very size of the system required for computing. Instead of using qubits they looked into ways of using qudits, which are quantum units of information allowing a multiple number of possible d-states (levels) where “d” is a variable.

The physicists have shown that using a single five-level qudits already enables full-scale quantum computing. For example, the complex Deutsch-Jozsa algorithm can be applied using the approach.

“We achieved some significant advantages, as in a number of their physical manifestations multilevel qudits are much easier to control than a system comprising a certain number of qubits; so we’re a step closer now to developing a real quantum computer. Multilevel units bring advantages in other quantum technologies as well, for example, in quantum cryptography,” said Alexander Fedorov from the Russian Quantum Center.