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Quantum BC Seminar Series – Rogério de Sousa

September 12, 2023 @ 2:00 pm - 3:00 pm

Join us on Tuesday, September 12 at 2pm for a seminar by Dr. Rogério de Sousa from the University of Victoria.


Title: Noise in Chip-Based Quantum Computers


Meeting ID: 694 4332 7772

Passcode: 996727

Abstract: Quantum computers are now available in several different chip-based technologies, but their quantum evolution is noisy, hindering demonstrations of quantum advantage over conventional computers. In this talk I will discuss the microscopic origin of electric and magnetic noise in the solid-state environment surrounding qubits. While some noise sources are intrinsic to the surfaces and interfaces within the chip [1], others are extrinsic in that they originate from impurities and defects within the materials forming the qubit [2, 3]. I will describe strategies to reduce the impact of noise on quantum computers using both hardware [4] and software [5] approaches.

[1] I. Diniz and R. de Sousa, Intrinsic Photon Loss at the Interface of Superconducting Devices, Phys. Rev. Lett. 125, 147702 (2020).
[2] N. Gorgichuk, T. Junginger, and R. de Sousa, Modeling Dielectric Loss in Superconducting Resonators : Evidence for Interacting Atomic Two-Level Systems at the Nb /Oxide Interface, Phys. Rev. Appl. 19, 024006 (2023).
[3] J.A. Nava Aquino and R. de Sousa, Flux Noise in Disordered Spin Systems, Phys. Rev. B 106, 144506 (2022).
[4] J.A. Nava Aquino and R. de Sousa, Model for 1/f flux noise in superconducting aluminum devices: Impact of external magnetic fields, Appl. Phys. Lett. 122, 224003 (2023).
[5] E. Wright and R. de Sousa, Fast quantum gate design with deep reinforcement learning using real-time feedback on readout signals, arXiv:2305.01169 [quant-ph].

Bio: Rogério de Sousa, Professor, Department of Physics and Astronomy, University of Victoria BC

Professor de Sousa obtained his B.Sc. in Physics at Universidade Estadual de Campinas, Brazil, and then moved to the USA to pursue a Ph.D. in physics and quantum computing at the University of Maryland, College Park. He was a postdoctoral fellow at the Departments of Chemistry and Physics at University of California, Berkeley, and moved to Canada in 2007 to join the Dept. of Physics and Astronomy at University of Victoria. His research group focuses on how to design quantum computing hardware and software with less noise.  They are implementing quantum algorithms in the current generation of noisy intermediate-scale quantum devices, and developing methods to benchmark as well as mitigate the impact of noise in them.

Prof. de Sousa is also interested in making quantum theory more accessible to people with different expertise. At UVic he teaches the course “Introductory Quantum Computing”, targeted at second-year science and engineering students with no previous exposure to quantum theory.


September 12, 2023
2:00 pm - 3:00 pm