The unimon, a new qubit to boost quantum computers for useful applications

The unimon is a new qubit that has been discovered by a group of scientists. The first quantum logic gates with unimons have been achieved by the team. The research was published in a journal.

Superconducting qubits are in the lead when it comes to building quantum computers. The current qubit designs and techniques are not high enough for practical applications. The implementation of quantum computations is limited by errors in single and two-qubit quantum gates. It is necessary that the quantum computations become more accurate.

We want to build quantum computers that can solve real world problems. Professor Mikko Mttnen, who is also a co- founder and chief scientist at IQM Quantum Computers, said that the announcement is an important milestone for the company.

The unimon is a new type of qubit which has the desired properties of increased anharmonicity, full insensitivity to DC charge noise, reduced sensitivity to magnetic noise, and a simple structure. The team was able to achieve fidelity from 99.8% to 99% for 13-nanoseconds-long single-qubit gates.

"Because of the higher anharmonicity, or non-linearity, than in transmons, we can operate the unimons faster, leading to fewer errors per operation," said Eric Hyypp who is working on his PhD.

Scientists designed and fabricated chips that contained three unimon qubits. Niobium was used instead of the Josephson junctions in order to make the leads.

The unimon qubit needed only a single Josephson junction without any superinductors and was protected against noise. The unimon has the potential for higher yield and predictability than junction-array based superinductors.

There are many advantages to unimons over transmons. The first unimon worked well and gave plenty of room for improvement. Prof. Mttnen said that we should show two-qubit gates as the next step.

We aim for further improvements in the design, materials, and gate time of the unimon to break the 99.99% fidelity target for useful quantum advantage with noisy systems. Prof. Mttnen said that this is a very exciting day.

The Unimon qubit, Nature Communications, is more information.

Journal information: Nature Communications