Quantum averaging theory for multitimescale driven quantum systems
Phys. Rev. A 113, 032210 – Published 13 March, 2026
DOI: https://doi.org/10.1103/jjvf-dw3l
Abstract
We present a multitimescale quantum averaging theory (QAT), a unitarity-preserving generalized Floquet framework for analytically modeling periodically and almost periodically driven quantum systems across multiple timescales. By integrating the Magnus expansion with the method of averaging on multiple scales, QAT captures the effects of both far-detuned and near-resonant interactions on system dynamics. The framework yields an effective Hamiltonian description while retaining fast oscillatory effects within a separate dynamical phase operator, ensuring accuracy across a wide range of driving regimes. We demonstrate the rapid convergence of QAT results toward exact numerical solutions in both detuning regimes for touchstone problems in quantum information science.
Physics Subject Headings (PhySH)
- Atomic & molecular processes in external fields
- Coherent control
- Quantum computation
- Quantum control
- Quantum correlations, foundations & formalism
- Quantum foundations
- Quantum protocols
- Quantum simulation
- Quantum state transfer
- Zeeman effect
- Adiabatic approximation
- Dipole approximation
- Nonperturbative methods
- Perturbative methods
- Phase space methods
- Rabi model
- Rotating wave approximation
- Schroedinger equation
- Two-level models
