Beecroft Building, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU
Professor Stéphane Guerin, Université Bourgogne Europe
Abstract
Control of quantum systems is at the core of quantum technologies, such as quantum computation based on quantum logical gates and quantum sensing. Such applications of quantum control require reaching a given target state (or propagator) with high fidelity via fast, ideally optimal, processes [1]. Physical implementations also impose robustness with respect to noise of the experimental parameters or to their imperfect knowledge. We develop a geometrical procedure, referred to as robust inverse optimization (RIO) [2-4], which allows a time- or energy- optimal pulse controls that are immune to errors. The procedure is demonstrated on IBM’s quantum computers via a digital version of RIO [5].
We also design optimal and robust stimulated Raman exact passage (STIREP), taking into account the presence of a lossy intermediate state [6].
Optimal control and RIO techniques find applications in the manipulation of Bose-Einstein condensates [1], including nonlinear effects [7], and in optimal quantum sensing [8]. Furthermore, they are shown to provide an energy shortcut of quantum protocols, which outperform Shortcut-To-Adiabaticity (STA) processes [9].
[1] Q. Ansel et al., J. Phys. B 57, 133001 (2024).
[2] G. Dridi, K. Liu, S. Guérin, Phys. Rev. Lett. 125, 250403 (2020).
[3] X. Laforgue, G. Dridi, S. Guérin, Phys. Rev. A 106, 052608 (2022).
[4] G. Dridi, X. Laforgue, M. Mejatty, S. Guérin, Phys. Rev. A (2024).
[5] M. Harutyunyan, F. Holweck, D. Sugny, and S. Guérin, Phys. Rev. Lett. 131, 200801 (2023).
[6] K. Liu, D. Sugny, X. Chen, and S. Guérin, Entropy 25, 790 (2023).
[7] J. Zhu and S. Guérin, Control of nonlinear quantum systems: From nonlinear Rabi oscillations to robust two-stage optimal inverse engineering, Phys. Rev. A 110, 063503 (2024).
[8] M. Harutyunyan, B. Peaudecerf, D. Sugny, and S. Guérin, Qubit sensing by optimal narrowband pulses (2025).
[9] C. L. Latune, M. B. Puthuveedu Shebeek, D. Sugny, S. Guérin, Energy shortcut of quantum protocols by optimal control (2025).