Optimal preparation of the W state for qubits with XY coupling
Abstract
Abstract Using simulated annealing, we find optimal protocols that evolve a simple product state into a three-qubit W state with a Hamiltonian that describes XY coupling and single-qubit gates, and determine the associated quantum speed limit. Applying Pontryagin's minimum principle, we fully characterize the optimal “bang-bang” protocols. While leakage affects performance, the protocols remain robust to implementation errors and operate well within relaxation and decoherence times. Our findings highlight Pontryagin's principle as a powerful tool for designing pulse shapes that directly link device interactions to specific quantum gates and target states.
Fields of Study & Subjects
Quantum Computing Algorithms and Architecture
Quantum Information and Cryptography
Quantum and electron transport phenomena
Publication details
- Journal / source
- Europhysics Letters (EPL)
- Publisher
- IOP Publishing
- Volume
- 154
- Issue
- 3
- Pages
- 38003–38003
- Publication date
- 7 April 2026