Extensible and Modular Advanced Qubits (EMAQs)
Abstract
The superconducting (SC) qubit modality is at the forefront of experimental quantum information processing, with single-qubit (two-qubit) fidelities exceeding (at) 99.9%, and prototype demonstrations of quantum error correction. Despite these achievements, building functional quantum processors requires further improvements to the qubits, their modularity, their control and coupling, and the understanding and mitigation of error sources. The Extensible and Modular Advanced Qubits (EMAQs) program addresses the modularity and extensibility of advanced qubits and qubit architectures through an integrated program that draws from each QC-S5 topical area: ¥ ModQ: Modular entangling gates between qubits on separate chips using waveguide QED. We begin with transmons and move to protected qubits, when proven ready. ¥ GASP: High-fidelity 1QB and 2QB gates in planar fluxonium and 0-pi qubits using geometries enabled by advanced fabrication and Floquet driving. ¥ FastCARS: Quartons to couple qubits and read them out faster and with higher fidelity ¥ NS5: Thermal and ionizing radiation and their resulting cascade dynamics (quasiparticles and phonons) for the design of quasiparticle mitigation strategies. EMAQs has assembled a strong, multi-disciplinary team of experimentalists and theorists with demonstrated expertise in the following areas critical to achieving QC-S5 goals: ¥ single-qubit and two-qubit operations with state-of-art transmon, C-shunt flux, and fluxonium qubits, as well as bosonic qubits and codes; ¥ calibration and benchmarking of small-scale qubit arrays (two qubits, 2x2, 3x3, 4x4); ¥ high-fidelity operations within both cavity QED and waveguide QED architectures; ¥ noise spectroscopy, dynamical error suppression, optimal control and Floquet methods; ¥ traveling-wave parametric amplifiers (TWPAs) and high-fidelity readout; ¥ ionizing radiation, quasiparticles, quasiparticle dynamics, and its mitigation ¥ high-Q materials growth, reproducible fabrication, and 3D integration. The experimental program at MIT leverages the following infrastructure and relationships: ¥ MIT.nano, a new fabrication facility comprising 47,000 ft2 of cleanroom space. ¥ dedicated sputtering tool and 4-chamber evaporator in MIT.nano. ¥ collaboration on fabrication, 3D integration, design, and experiments with MIT Lincoln Laboratory (funded separately); PIs Oliver and Serniak carry joint appointments. The EMAQs program addresses the demonstration of protected qubits (GASP) and modular, remote entangled gates (ModQ). FastCARS and NS5 thrusts support the GASP and ModQ research. FastCARS develops coupler and readout elements that enable fast, high-fidelity coupling and readout. The NS5 thrust studies ionizing radiation and the dynamics of quasiparticles and their mitigation, all of which will improve qubit performance and extensibility.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 08, 2023
- Source ID
- W911NF2310045
Entities
People
- William D Oliver
Organizations
- Army Contracting Command
- Massachusetts Institute of Technology
- National Security Agency