Option 1: Charge Parity Qubit Protected Against Local Noise
Abstract
We propose a novel logical qubit that relies on the hybrid fabrication of conventional submicron Al-AlOx-Al junctions and high kinetic inductivity nanowires based on strongly disordered superconductors: the charge-parity (C-parity) qubit. The hybrid structure allows realization of a composite Josephson element that displays robust p-periodicity of the Josephson energy. Small arrays of such elements provide exponential suppression of the sensitivity to local noises. Moreover, two orthogonal controls that couple to the charge and phase degrees of freedom permit arbitrary Clifford group rotations in the protected subspace. Our novel approach circumvents the problems that have doomed previous designs of topologically protected qubits, namely: (1) thermal excitation out of the protected subspace to low-lying excited states and (2) offset charges on the superconducting islands and fragile pi-periodicity that make protection inefficient. The proposed work will leverage prior successes in realizing excellent contact between aluminum and the disordered superconductor, along with an established suite of qubit characterization tools. The program represents a close collaboration between experimenters and theorists, and real-time feedback from the theory team will guide device optimization and facilitate rapid progress. The compact footprint of the protected C-parity qubit is readily scalable using standard integrated circuit technology; as a result, the successful pursuit of this program will represent a major step toward realization of scalable quantum information processing in the solid state.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 14, 2019
- Source ID
- W911NF1810106
Entities
People
- Robert Mcdermott
Organizations
- Army Contracting Command
- National Security Agency
- University of Wisconsin–Madison