Pulse engineering via projection of response functions (2404.10462v4)
Abstract: We present an iterative optimal control method of quantum systems, aimed at an implementation of a desired operation with optimal fidelity. The update step of the method is based on the linear response of the fidelity to the control operators, and its projection onto the mode functions of the corresponding operator. Our method extends methods such as gradient-ascent pulse engineering (GRAPE) and variational quantum algorithms, by determining the fidelity gradient in a hyperparameter-free manner, and using it for a multiparameter update, capitalizing on the multimode overlap of the perturbation and the mode functions. This directly reduces the number of dynamical trajectories that need to be evaluated in order to update a set of parameters. We demonstrate this approach, and compare it to the standard GRAPE algorithm, for the example of a quantum gate on two qubits, demonstrating a clear improvement in convergence and optimal fidelity of the generated protocol.
- J. P. Palao and R. Kosloff, Optimal control theory for unitary transformations, Phys. Rev. A 68, 062308 (2003).
- P. Rebentrost and F. K. Wilhelm, Optimal control of a leaking qubit, Phys. Rev. B 79, 060507 (2009).
- D. J. Egger and F. K. Wilhelm, Optimized controlled-z gates for two superconducting qubits coupled through a resonator, Superconductor Science and Technology 27, 014001 (2013).
- S. Jandura and G. Pupillo, Time-Optimal Two- and Three-Qubit Gates for Rydberg Atoms, Quantum 6, 712 (2022).
- R. de Keijzer, O. Tse, and S. Kokkelmans, Pulse based Variational Quantum Optimal Control for hybrid quantum computing, Quantum 7, 908 (2023).
- L. Bittel, J. Watty, and M. Kliesch, Fast gradient estimation for variational quantum algorithms (2022), arXiv:2210.06484 [quant-ph] .
- J. Preskill, Quantum Computing in the NISQ era and beyond, Quantum 2, 79 (2018).
- L. Bittel and M. Kliesch, Training variational quantum algorithms is np-hard, Phys. Rev. Lett. 127, 120502 (2021).
- E. R. Anschuetz and B. T. Kiani, Quantum variational algorithms are swamped with traps, Nature Communications 13, 7760 (2022).
- L. Broers and L. Mathey, Mitigated barren plateaus in the time-nonlocal optimization of analog quantum-algorithm protocols, Phys. Rev. Res. 6, 013076 (2024).
- A. Castro and I. V. Tokatly, Quantum optimal control theory in the linear response formalism, Phys. Rev. A 84, 033410 (2011).
- P. Doria, T. Calarco, and S. Montangero, Optimal control technique for many-body quantum dynamics, Phys. Rev. Lett. 106, 190501 (2011).
- T. Caneva, T. Calarco, and S. Montangero, Chopped random-basis quantum optimization, Phys. Rev. A 84, 022326 (2011).
Paper Prompts
Sign up for free to create and run prompts on this paper using GPT-5.
Top Community Prompts
Collections
Sign up for free to add this paper to one or more collections.
