Fluxonium Qubit Retains Information For 1.43 Milliseconds – 10x Longer Than Before

Science Alert  July 6, 2023 An international team of researchers (USA- University of Maryland, Switzerland) has built a fluxonium qubit that could retain information for 1.43 milliseconds. The superconducting fluxonium qubit had uncorrected coherence time T∗2=1.48±0.13ms, exceeding the state of the art for transmons by an order of magnitude. The average gate fidelity was benchmarked at 0.99991(1). Even in the millisecond range, the coherence time was limited by material absorption and could be further improved with a more rigorous fabrication. According to the researchers their demonstration may be useful for suppressing errors in the next generation quantum processors… read more. […]

A quantum leap in computational performance of quantum processors

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 […]

New quantum computing architecture could be used to connect large-scale devices

Science Daily  January 5, 2023 Quantum information transfer between arbitrary nodes is generally mediated either by photons that propagate between them or by resonantly coupling nearby nodes. The utility is determined by the type of emitter, propagation channel and receiver. Conventional approaches involving propagating microwave photons have limited fidelity due to photon loss and are often unidirectional, whereas architectures that use direct resonant coupling are bidirectional in principle but can generally accommodate only a few local nodes. Researchers at MIT have demonstrated high-fidelity, on-demand, directional, microwave photon emission by using an artificial molecule comprising two superconducting qubits strongly coupled to […]