Institute of Computer Science AGH and IBM Software Laboratory in Krakow invite to Krakow Quantum Informatics Seminar (KQIS)
• understand and discuss current problems in quantum informatics,
• discuss new quantum computing technologies,
• exchange ideas and research results,
• integrate information across different research teams,
• build a community around quantum informatics.

Program: Tuesday, November 9th, 2021 9:30-11:00

Julia Plewa, AGH graduate & BNP Paribas

Joanna Sieńko, AGH graduate

Temat: Comparison of quantum optimization algorithms and encoding schemes for workflow scheduling



In this presentation, we will consider the trade-off between space efficiency and circuit complexity in the context of a specific optimization problem – workflow scheduling. We will compare three encoding schemes of varying density: one-hot, binary [2], and domain wall [1], and test their performance against two hybrid quantum-classical algorithms: QAOA and VQE. We will also discuss the various parameters of the algorithms and other state-of-the-art improvements, such as dedicated QAOA mixers. We will present the results of our experiments that were run using the Qiskit simulator [3]. Ultimately, we will prove that one-hot encoding is not always the best, and that using a denser encoding scheme, such as binary or domain wall, can allow for encoding larger problems and sometimes even for better results.


[1] Chancellor N.: Domain wall encoding of discrete variables for quantum annealing and QAOA. In: Quantum Science and Technology, vol. 4(4), p. 045004, 2019. URL

[2] Glos A., Krawiec A., Zimborás Z.: Space-efficient binary optimization for variational computing. arXiv:quant-ph/2009.07309, 2020.

[3] Plewa J., Sienko J.: Hybrid algorithms for workflow scheduling problem in quantum devices based on gate model. Master’s thesis supervised by Katarzyna Rycerz, PhD, Institute of Computer Sciece, AGH University of Science and Technology, Krakow, September 2021. URL


Julia Plewa received her M.Sc. degree in computer science in 2021 from the AGH University of Science and Technology in Kraków, Poland. Her research interests include driver behavior modeling and quantum computing. She currently works as a quantum computing researcher at BNP Paribas.

Joanna Sieńko received her M.Sc. degree in computer science in 2021 from the AGH University of Science and Technology in Kraków, Poland. Her interests include object-oriented programming, microservices, and cloud computing. She currently works as a software engineer at an e-commerce company.

  • 2 years, 7 months ago