A cohort of physicists affiliated with the University of Oxford has attained the most precise quantum logic operation ever documented, achieving an error rate of a mere 0.000015%, equating to a single mistake per 6.7 million operations.
A rendering of the ion trap chip. Image credit: Jochen Wolf & Tom Harty, University of Oxford.
“To our knowledge, this represents the most accurate qubit operation ever registered globally,” stated Professor David Lucas from the University of Oxford.
“This achievement is a pivotal advancement towards the realization of practical quantum computers capable of addressing complex real-world challenges.”
For a quantum computer to perform meaningful computations, an immense number of operations, potentially in the millions, must be executed across numerous qubits.
Consequently, if the error rate proves excessively high, the ultimate outcome of any calculation will be rendered invalid.
While error correction mechanisms can be implemented to rectify inaccuracies, this invariably necessitates a substantially larger quantity of qubits.
Through the reduction of error probabilities, the novel methodology curtails the demand for qubits, thereby diminishing the overall cost and physical footprint of the quantum computing apparatus.
“By substantially minimizing the likelihood of error, this research significantly alleviates the infrastructural demands associated with error correction, paving the way for future quantum computers to be more compact, swifter, and more resource-efficient,” remarked Molly Smith, a graduate student at the University of Oxford.
“Furthermore, the refined control over qubits will prove advantageous for other quantum technologies, including atomic clocks and quantum sensing devices.”
This remarkable degree of accuracy was accomplished utilizing a trapped calcium ion, which served as the qubit.
These ions are intrinsically well-suited for the storage of quantum information due to their extended coherence times and inherent stability.
Diverging from conventional techniques that employ lasers, the research team modulated the quantum states of the calcium ions through electronic (microwave) signals.
This alternative approach offers superior stability in comparison to laser-based control and presents additional advantages pertinent to the construction of functional quantum computers.
For instance, electronic control is considerably more economical and resilient than laser systems and facilitates simpler integration within ion trapping architectures.
Moreover, the experimental work was conducted under ambient temperature conditions and without the need for magnetic shielding, thereby simplifying the engineering prerequisites for an operational quantum computer.
“While this record-setting outcome signifies a major breakthrough, it is intrinsically linked to a broader, ongoing challenge,” the authors noted.
“Quantum computation requires the synchronized operation of both single-qubit and two-qubit gates.”
“Presently, two-qubit gates exhibit considerably higher error rates — standing at approximately 1 in 2,000 in the most advanced demonstrations to date — thus, their refinement will be paramount for the development of fully fault-tolerant quantum systems.”
Their research findings have been published online in the esteemed journal Physical Review Letters.
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M.C. Smith et al. 2025. Single-qubit gates with errors at the 10−7 level. Phys. Rev. Lett, in press; doi: 10.1103/42w2-6ccy
