Quantum Computing - Robust Quantum Limited Isolation and Amplification with Traveling Wave Parametric Devices
Abstract
Broadband quantum limited amplifiers are a key supporting technology for gate-based superconducting quantum computing and likely for spin-based quantum computers, enabling fast multiplexed high fidelity qubit readout which is critical for quantum error correction. Josephson traveling wave parametric amplifiers (JTWPAs) are a widely used workhorse. More than three hundred of these devices, based on our theory and design work, have been fabricated and distributed by Lincoln Lab in support of AF, DoD, and other US government programs to enable rapid high fidelity cryogenic microwave frequency qubit readout; however, uniform JTWPAs have shortcomings which will hold back progress towards error corrected quantum computers. The principle non-idealities to be addressed in this proposal are (a) 0 dB reverse gain, meaning downstream noise (e.g., from higher temperature stages) is not blocked and can decohere the qubits, requiring large highly magnetic cryogenic isolators after the amplifier, (b) reverse gain due to backward wave mixing processes, requiring an isolator before the amplifier, (c) the noise performance remains a factor of 2 away from the best that quantum mechanics allows and (d) their performance depends on the out-of-band impedance, leading to ripples and instabilities.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 06, 2025
- Source ID
- FA95502410137
Entities
People
- Kevin O Brien
Organizations
- Air Force Office of Scientific Research
- Massachusetts Institute of Technology
- United States Air Force