IMX Seminar Series - Impact of materials on loss in superconducting qubits

Progress achieved in the field of quantum computing has enabled new platforms for solving problems on the path towards surpassing their classical counterparts.  A critical link in maintaining these advancements is identifying which constraints pose the greatest limitations on qubit performance.  After a brief introduction to superconducting transmon qubits, I will describe several mechanisms that are responsible for the relaxation or decoherence of their state and the corresponding methods that can be utilized to characterize their influence.  A combination of analytical and computational approaches can be used to guide both the design of qubits and the metallization that comprises them, allowing for a more accurate comparison of parameters that can influence their manufacture and operation.  I will also detail how these aspects provide a framework for understanding the evolution of IBM’s offerings in the era of near-term quantum computing. 

Suggested references: 

C.E. Murray, “Material matters in superconducting qubits”, Mat. Sci. Eng. R: Reports 146, 100646 (2021)   (arxiv2106.05919)

C. Kurter et al., “Quasiparticle tunneling as a probe of Josephson junction quality and capacitor material in superconducting qubits”, arxiv2106.11488

Bio: Conal E. Murray received a Sc.B. degree in mechanics and materials science from Harvard University, M.S. in mechanical engineering from Boston University, and a Ph.D. in materials science and engineering from Northwestern University in 2000.  Since completing his Ph.D., he has been a Research Staff Member at the IBM T.J. Watson Research Center in Yorktown Heights, NY, where his research focuses on the study of loss mechanisms associated with quantum computing and the micromechanics of semiconductor devices.  Dr. Murray has received 4 IBM Research Division awards, the IEEE 2017 Van Duzer prize and was elected a Fellow of the American Physical Society in 2018.  He has authored or co-authored over 100 scientific publications, 3 book chapters, and holds over 90 patents.  He served as co-chair of the 2019 MRS Fall Meeting and has been on the organizing committee of the Denver X-ray Conference since 2012.