Phys.org April 24, 2023
An international team of researchers (Israel, Germany, UAE) is improving the performance of superconducting qubits, the basic computation units of a superconducting quantum processor. They studied a series of tunable flux qubits inductively coupled to a coplanar waveguide resonator fabricated on a sapphire substrate. Each qubit included an asymmetric superconducting quantum interference device, which is controlled by the application of an external magnetic field and acts as a tunable Josephson junction. The tunability of the qubits is typically ±3.5GHz around their central gap frequency. The measured relaxation times are limited by dielectric losses in the substrate and can attain T1∼8μs. The echo dephasing times are limited by flux noise even at optimal points and reach T2E∼4μs. They showed that they could not only control the production of the qubits, but also actively change their frequency without compromising their performance. Superconducting flux qubits are very fast and reliable, and it may be simpler to integrate many flux qubits into a processor compared to current available technology… read more. TECHNICAL ARTICLE
Energy relaxation and spin-echo measurements of qubit 3 at optimal points Ï€ and 5Ï€… Credit: Phys. Rev. Applied 19, 024066, 24 February 2023Â