QC-S5 ModQ: Modular Superconducting Processors Via Parametric Couplings, Lossy Links, and Fast Switches
Abstract
Despite their small size and incredible operation speeds, semiconducting spin qubits hosted in silicon-germanium (SiGe) heterostructures with a silicon or germanium quantum well are limited by material noise and the scaling of control and readout parameters. However, their sensitivity to electric fields can be turned useful if a sufficiently large number of gate voltages can be adjusted accurately (low-frequency control) and tuned quickly (high-frequency control), and if online control feedback happens faster than the coherence times associated with the qubits. To achieve such online quantum control with high fidelities, we leverage recent technology breakthroughs in several areas: device fabrication of small-scale two-dimensional SiGe arrays, quantum-classical interfacing, real-time quantum control with advanced FPGA-based high-frequency digitizers and generators, and the adaption of algorithms for the specific quantum and control hardware. We will implement multi-qubit classification with fast FPGA-based neural networks, on-board detection and calibration of processor and drive-line anomalies, and qubit stabilization based on real-time Hamiltonian estimation (Year 1). By acquiring simultaneous multi-qubit single-shot readouts, we will execute dynamical decoupling schemes that measure qubit-qubit noise correlations; these results will then be used to implement real-time feedback, optimizing gate fidelity and maximising processor uptime (Year 2). To show direct relevance for ongoing state-ofthe- art development, we will in Year 3 and 4 apply our results to a small-scale two-dimensional spin-qubit processor, demonstrating adaptive readout and fidelity improvement, mid-circuit measurement and noise assessment, as well as quantum gates conditioned on a previous qubit spin-to-charge conversion.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 16, 2023
- Source ID
- W911NF2310253
Entities
People
- Michael Hatridge
Organizations
- Army Contracting Command
- National Security Agency
- University of Pittsburgh