arXiv subjects

Gregoire Charlot

Publications and source records attributed to Gregoire Charlot.

2 recordsLinked to original sources

arXiv2005

Nonisotropic 3-level Quantum Systems: Complete Solutions for Minimum Time and Minimum Energy

We apply techniques of subriemannian geometry on Lie groups and of optimal synthesis on 2-D manifolds to the population transfer problem in a three-level quantum system driven by two laser pulses, of arbitrary shape and frequency. In the rotating wave approximation, we consider a nonisotropic model i.e. a model in which the two coupling constants of the lasers are different. The aim is to induce transitions from the first to the third level, minimizing 1) the time of the transition (with bounded laser amplitudes), 2) the energy of lasers (with fixed final time). After reducing the problem to real variables, for the purpose 1) we develop a theory of time optimal syntheses for distributional problem on 2-D-manifolds, while for the purpose 2) we use techniques of subriemannian geometry on 3-D Lie groups. The complete optimal syntheses are computed.

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arXiv2004

Resonance of Minimizers for $n$-level Quantum Systems with an Arbitrary Cost

We consider an optimal control problem describing a laser-induced population transfer on a $n$-level quantum system. For a convex cost depending only on the moduli of controls (i.e. the lasers intensities), we prove that there always exists a minimizer in resonance. This permits to justify some strategies used in experimental physics. It is also quite important because it permits to reduce remarkably the complexity of the problem (and extend some of our previous results for $n=2$ and $n=3$): instead of looking for minimizers on the sphere $S^{2n-1}\subset\C^n$ one is reduced to look just for minimizers on the sphere $S^{n-1}\subset \R^n$. Moreover, for the reduced problem, we investigate on the question of existence of strict abnormal minimizer.

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