Phys.org December 10, 2024 Qubit connectivity on a planar surface is typically restricted to only a few neighboring qubits. Overcoming the complex multilayer packaging, external cabling, and fidelity limitations, a team of researchers in the US (University of Chicago, Argonne National Laboratory) proposed and developed a high-speed on-chip quantum processor that supported reconfigurable all-to-all coupling with a large on-off ratio. They implemented the design in a four-node quantum processor, built with a modular design comprising a wiring substrate coupled to two separate qubit-bearing substrates, each including two single-qubit nodes. Using the device they demonstrated reconfigurable controlled- gates across all qubit […]
Tag Archives: Quantum circuit
All-nitride superconducting qubit made on a silicon substrate
Science Daily September 20, 2021 Researchers in Japan have developed superconducting qubits based on NbN/AlN/NbN epitaxial Josephson junctions on silicon substrates which promise to overcome the drawbacks of qubits based on Al/AlOx/Al junctions. The all-nitride qubits have great advantages such as chemical stability against oxidation, resulting in fewer two-level fluctuators, feasibility for epitaxial tunnel barriers that reduce energy relaxation and dephasing, and a larger superconducting gap of ~5.2 meV for NbN, compared to ~0.3 meV for aluminum, which suppresses the excitation of quasiparticles. By replacing conventional MgO by a silicon substrate with a TiN buffer layer for epitaxial growth of […]