IMX Seminar Series - Materials for Superconducting Quantum Computing

Abstract : The superconducting transmon qubit is a leading platform for quantum computing and quantum science. Building large, useful quantum systems based on transmon qubits will require significant improvements in qubit relaxation and coherence times, which are orders of magnitude shorter than limits imposed by bulk properties of the constituent materials. This indicates that relaxation likely originates from uncontrolled surfaces, interfaces, and contaminants. Previous efforts to improve qubit lifetimes have focused primarily on designs that minimize contributions from surfaces. However, significant improvements in the lifetime of two-dimensional transmon qubits have remained elusive for several years. We will present a materials-based approach to reliably reproduce long coherence times by using tantalum-based devices, and present detailed characterization of devices to understand remaining sources of decoherence.

Papers:  Place et al, Nature Communications volume 12, Article number: 1779 (2021)
Hazard et al, Phys. Rev. Lett. 122, 010504 (2019)
Bio: Andrew Houck is a professor in the Department of Electrical Engineering at Princeton University and Director of the Princeton Quantum Institute. His current research centers on quantum computing and quantum simulation with superconducting circuits. Specific projects include discovering and implementing novel qubits, materials for quantum information, and using graph theory to inform lattice design for building artificial quantum materials. He teaches quantum information and has helped developed a new series of freshman physics and math courses that significantly reduces the achievement gap among first year students. Houck serves as the Director of the Co-Design Center for Quantum Advantage, a DOE center run out of Brookhaven National Laboratory.