Microscopic relaxation channels in materials for superconducting qubits
| Autor: | Andi Barbour, Ignace Jarrige, Sooyeon Hwang, Alexander Place, Mike S. Miller, Jonathan Pelliciari, Paola Russo, Mark S. Hybertsen, Andrew Houck, Conan Weiland, Anjali Premkumar, Fernando Camino, Berthold Jäck, Kim Kisslinger, Xiao Tong, Iradwikanari Waluyo, Adrian Hunt, Valentina Bisogni |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Niobium FOS: Physical sciences chemistry.chemical_element Applied Physics (physics.app-ph) 02 engineering and technology 01 natural sciences Computer Science::Emerging Technologies Condensed Matter::Superconductivity 0103 physical sciences Figure of merit General Materials Science 010306 general physics Materials of engineering and construction. Mechanics of materials Superconductivity Condensed Matter - Materials Science Quantum Physics Condensed matter physics Relaxation (NMR) Materials Science (cond-mat.mtrl-sci) Physics - Applied Physics Transmon 021001 nanoscience & nanotechnology Grain size chemistry Mechanics of Materials Qubit TA401-492 Grain boundary Quantum Physics (quant-ph) 0210 nano-technology |
| Zdroj: | Communications Materials, Vol 2, Iss 1, Pp 1-9 (2021) |
| ISSN: | 2662-4443 |
| DOI: | 10.1038/s43246-021-00174-7 |
| Popis: | Despite mounting evidence that materials imperfections are a major obstacle to practical applications of superconducting qubits, connections between microscopic material properties and qubit coherence are poorly understood. Here, we combine measurements of transmon qubit relaxation times (T1) with spectroscopy and microscopy of the polycrystalline niobium films used in qubit fabrication. By comparing films deposited using three different techniques, we reveal correlations between T1 and intrinsic film properties such as grain size, enhanced oxygen diffusion along grain boundaries, and the concentration of suboxides near the surface. Qubit and resonator measurements show signatures of two-level system defects, which we propose to be hosted in the grain boundaries and surface oxides. We also show that the residual resistance ratio of the polycrystalline niobium films can be used as a figure of merit for qubit lifetime. This comprehensive approach to understanding qubit decoherence charts a pathway for materials-driven improvements of superconducting qubit performance. Understanding the connection between qubit coherence and microscopic materials properties is vital for improving device performance. Here, the relaxation times of superconducting transmon qubits are found to be directly correlated with Nb film properties such as grain size and surface oxide composition. |
| Databáze: | OpenAIRE |
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