Q-CASA Invited Speaker Structured noise in quantum computers: an obstacle or an opportunity?

• Published in: 2023 IEEE International Parallel and Distributed Processing Symposium Workshops (IPDPSW) p. 497
• Main Author: Kapit, Eliot
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.05.2023
• DOI: 10.1109/IPDPSW59300.2023.00085

The single greatest challenge in building workable quantum computers is noise, arising from uncontrolled interactions between qubits and their surrounding environment. In superconducting circuits-one of the most advanced, and broadly studied, qubit modalities-this noise has distinctive spectral features that are fairly universal across a wide array of qubit designs. In recent years, clever techniques to exploit this structure through the use of AC driving, coupling to intentionally lossy objects, and strong qubit-qubit interactions have led to innovative new qubit designs that would be impractical or even impossible in other platforms. In this talk, I provide an overview of important new results in this area, with special focus on two recent advances from my group. First, I will discuss the Star Code, a fully autonomous error correction protocol using just two tunably coupled transmon qubits, which was successfully demonstrated in a recent experiment. Second, I will describe the Cold Echo Qubit architecture, which consists of two or three strongly coupled flux-type qubits subject to strong, continuous AC drives, suppressing all single qubit error channels in a similarly autonomous manner. Finally, I will sketch how these devices might be incorporated as an autonomous "base layer" of a larger digital error correction code, and how the core principles of their operation can inspire novel quantum algorithms for quantum simulation and optimization.