While tremendous progress has been made with certain types of qubits, such as superconducting qubits and trapped ion qubits, much room remains for exploring and enhancing their properties. One example would be increasing their “coherence times,” that is, the time for which they can be usefully employed in a quantum sense.
Researchers are also searching for entirely new qubit systems with better coherence, scalability, measurement access, and ease of fabrication and operation.
Also being pursued is the ability to convert or “transduce” information across qubit types to trade-off one physical property for another. For instance, one type of qubit may have better coupling properties, and another may be easier to transport.
Consequently, many of our projects in this area focus on the development and characterization of materials and devices for next-generation quantum information systems with these issues in mind. For example, recent Argonne efforts enabled by the Advanced Photon Source and the Center for Nanoscale Materials, both U.S. Department of Energy Office of Science User Facilities, have mapped out qubit/environmental interactions, such as spin/strain effects, and developed new sources for producing single and entangled photons.