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arXiv · 1806.02738

Magnus expansion for a chirped quantum two-level system

Peter Nalbach·Vicente Leyton
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Abstract

We derive a Magnus expansion for a frequency chirped quantum two-level system. We obtain a time-independent effective Hamiltonian which generates a stroboscopic time evolution. At lowest order the according dynamics is identical to results from using a rotating wave approximation. We determine, furthermore, also the next higher order corrections within our expansion scheme in correspondence to the Bloch-Siegert shifts for harmonically driven systems. Importantly, our scheme can be extended to more complicated systems, i.e. even many-body systems.

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Peter Nalbach, Vicente Leyton. 2018-06-07. Magnus expansion for a chirped quantum two-level system. https://doi.org/10.1103/physreva.98.023855

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