This NIRT proposal focuses on the design, fabrication and characterization of a fundamentally new class of fault-tolerant logical elements of a quantum computer (a.k.a. qubits). For successful implementation of quantum computing, qubits should be sufficiently decoupled (protected) from the environment so that quantum error-correction protocols can be implemented. The proposed novel approach to this challenging problem is based on incorporating error correction at the hardware level, using nontrivial symmetries and engineering the interactions between superconducting elements (nanoscale Josephson junctions) of a logical qubit.
Intellectual Merit: The proposed systematic effort is based on a continuous feedback loop between theory and experiment. The ultimate goal of the project is to develop the first solid-state logical element for quantum computation that would be simultaneously scalable and adequately protected from environmental noise. Development of fabrication-friendly designs for protected superconducting qubits, and the subsequent construction and characterization of these novel nanodevices will be crucial for the successful realization of quantum computation. The proposed experiments will provide a testing ground for the physical realization of ideas of symmetry-based protection developed in field theory, with the aim of applying them to computer science. Implementation of the proposed research will contribute to better understanding of noise reduction in numerous quantum nanodevices operating at low temperatures.
Broader Impacts: The multi-component Educational and Outreach Program, an essential part of the project, is designed to nurture a broad-based appreciation for nanoscience, to develop innovative curriculum and training modules on nanostructure-related topics, and to disseminate the resulting curricula with a view of creating a more scientifically literate general public.