| AVS 66th International Symposium & Exhibition | |
| Materials and Processes for Quantum Information, Computing and Science Focus Topic | Monday Sessions |
| Session QS+EM+MN+NS-MoM |
| Session: | High Coherence Qubits for Quantum Computing |
| Presenter: | Christopher Richardson, Laboratory for Physical Sciences |
| Authors: | C.J.K. Richardson, Laboratory for Physical Sciences A. Alexander, Laboratory for Physical Sciences C. Weddle, Laboratory for Physical Sciences M. Olszta, Pacific Northwest National Laboratory B. Arey, Pacific Northwest National Laboratory |
| Correspondent: | Click to Email |
Low microwave loss superconducting circuit components are a necessity of fabricating high-fidelity superconducting qubits. Accordingly, significant research has focused on making high-quality planar resonators from elemental and nitride superconductors. Josephson junctions are the nonlinear component of superconducting qubits, that also need to be high performance. Interestingly, superconducting qubits all use Josephson junctions fabricated from aluminum and aluminum oxide using the double angle evaporation process. Details of this alternative design will be presented.
Plasma assisted Molecular beam epitaxy (PAMBE) is used to grow niobium titanium nitride alloys (NbxTi1-xN) and wide bandgap nitride (AlN) superconductors directly on sapphire wafers. This combination of nitride materials provides sufficient degrees of freedom that synthesis of an epitaxial Josephson junction may be possible. Using a structure first approach to design optimization, the structural, surface topology, chemical characteristics, and superconducting critical temperature of these films are used for optimization of the growth conditions before resonators are fabricated and tested.
Growth results of NbTiN and AlN films, bi-layer insulator-superconductor structures and trilayer superconductor-insulator-superconductor structures will be presented along with superconducting properties.