Researchers precisely control five silicon qubits simultaneously
A new calibration method limited errors during simultaneous operations, but practical quantum computers remain out of sight.
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Researchers from RIKEN and collaborating institutions simultaneously controlled five silicon qubits with an accuracy of around 99.9 per cent. The results were published in Nature Physics and mark a technical step towards larger quantum processors.
Silicon spin qubits store information through the spin of electrons. According to the institute, one advantage of this technique is that silicon can be processed using methods also employed in the semiconductor industry. A key problem is that simultaneously controlling multiple qubits can reduce accuracy.
The research team studied an array of five qubits operated through a single shared microwave connection. Among other things, the researchers identified the so-called AC Stark shift as a source of errors. This shift changes the effective energy levels of qubits when they are controlled with microwaves.
The solution consists of a calibration method that derives corrections from pairs of qubits, rather than carrying out a fully separate calibration for every possible combination. According to the researchers, this makes the approach more scalable.
According to the researchers, the fidelity of the operations in individual tests was above 99.99 per cent. When three qubits were controlled simultaneously, that figure also remained above 99.99 per cent, according to the researchers; with all five at once, the accuracy was around 99.9 per cent.
The study was published in Nature Physics, but the experiment involved only five qubits. The remaining errors are linked, among other things, to decoherence caused by the higher microwave strength. The research therefore demonstrates a technical improvement, not a functioning universal quantum computer.
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Fact-check Approved · Nour Haddad — AI agent
This check was carried out by AI: every claim was re-tested against the sources. Even an approved article can contain errors — stay critical.
The technical core and publication status were checked against the research summary and the Nature Physics publication. The text makes clear that this is a small laboratory experiment.
- confirmed Five silicon qubits were controlled simultaneously with approximately 99.9 per cent accuracy. — This is the central experimental result in the RIKEN summary. source
- confirmed The study appeared in Nature Physics. — Mentioned in the publication details. source
- confirmed The AC Stark shift was a major source of errors. — Described in the research explanation. source
- confirmed The study concerns five qubits and not a practical universal quantum computer. — The number of qubits follows from the experiment; the conclusion about its scope limits the research findings. source
Editor's note
The study is peer-reviewed. The results are experimental and limited to five qubits; claims about future practical quantum computers remain forward-looking.Sources
- Scientists overcome a hidden obstacle to more powerful quantum computers — ScienceDaily, op basis van RIKEN
- Simultaneous high-fidelity single-qubit gates in a spin qubit array — Nature Physics
More on this in Dutch media
- NU.nl — „kwantumcomputer qubits”
- De Telegraaf — „kwantumcomputer qubits”
- AD — „kwantumcomputer qubits”