Precise tuning of quantum gates without compromising readout ⚡ экспресс
In a superconducting quantum chip with two qubits (transmons) connected by a tunable bridge, they managed to simultaneously achieve record fidelity for the main operations: the two-qubit CZ gate at 99.93%, single-qubit gates at 99.98%, and readout above 99.94%. The key is fine-tuning the coupling strength, a new calibration protocol called PALEA, and a compatible readout scheme. It's like a race car where the engine, brakes, and steering all work flawlessly together. This approach paves the way toward scalable quantum processors without loss of quality.
A quantum processor is like an orchestra, where qubit musicians can play two notes at once. The dream of such machines was laid by Richard Feynman and David Deutsch. For the orchestra to sound harmonious, 'gates' are needed—commands that change notes. But previously, tuning one group of musicians drowned out others: improving the accuracy of single qubits spoiled pair interactions and the recording of the final melody.
Scientists found a way to conduct so that all instruments played clearly. By adjusting the coupling strength between qubits, they applied a protocol that eliminates rare false notes—states that go beyond the desired level. As a result, the 'orchestra' achieved accuracy comparable to one mistake per ten thousand notes.
This success is not a breakthrough into the mysteries of the Standard Model of particle physics, but a triumph of engineering, where tuning frequencies resembles spectroscopy—the method of determining the composition of stars by light. Such precision opens the way to computers capable of correcting their own errors.
🎯 Superconducting qubits operate at temperatures a few hundredths of a degree above absolute zero—colder than outer space.
🎬 In science fiction films, a quantum computer is often portrayed as an oracle solving any problem—the reality is more modest, but no less astonishing.