0000000000023552

AUTHOR

Q. Ansel

showing 3 related works from this author

Robust optimal control of two-level quantum systems

2017

We investigate the time and the energy minimum optimal solutions for the robust control of two-level quantum systems against offset or control field uncertainties. Using the Pontryagin Maximum Principle, we derive the global optimal pulses for the first robustness orders. We show that the dimension of the control landscape is lower or equal to 2N for a field robust to the N th order, which leads to an estimate of its complexity.

Physics0209 industrial biotechnologyQuantum PhysicsOffset (computer science)Field (physics)Order (ring theory)FOS: Physical sciences02 engineering and technologyOptimal control01 natural sciences020901 industrial engineering & automationDimension (vector space)Robustness (computer science)0103 physical sciencesApplied mathematicsRobust control010306 general physicsQuantum Physics (quant-ph)Quantum
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Optimal control of an inhomogeneous spin ensemble coupled to a cavity

2018

We apply optimal control techniques to an inhomogeneous spin ensemble coupled to a cavity. A general procedure is proposed for designing the control strategies. We numerically show the extent to which optimal control fields robust against system uncertainties help enhancing the sensitivity of the detection process. The parameters of the numerical simulations are taken from recent Electron Spin Resonance experiments. The low and high cooperativity regimes are explored.

Physics[PHYS]Physics [physics]Quantum PhysicsProcess (computing)FOS: Physical sciencesCooperativity02 engineering and technology021001 nanoscience & nanotechnologyOptimal control01 natural scienceslaw.inventionlaw0103 physical sciencesSensitivity (control systems)Statistical physics010306 general physics0210 nano-technologyElectron paramagnetic resonanceQuantum Physics (quant-ph)Spin-½
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Time-optimal selective pulses of two uncoupled spin-1/2 particles

2018

We investigate the time-optimal solution of the selective control of two uncoupled spin 1/2 particles. Using the Pontryagin Maximum Principle, we derive the global time-optimal pulses for two spins with different offsets. We show that the Pontryagin Hamiltonian can be written as a one-dimensional effective Hamiltonian. The optimal fields can be expressed analytically in terms of elliptic integrals. The time-optimal control problem is solved for the selective inversion and excitation processes. A bifurcation in the structure of the control fields occurs for a specific offset threshold. In particular, we show that for small offsets, the optimal solution is the concatenation of regular and sin…

PhysicsQuantum Physics0209 industrial biotechnologySelective controlSpinsMathematical analysisFOS: Physical sciences02 engineering and technologyTime optimal01 natural sciencesPontryagin's minimum principle020901 industrial engineering & automation0103 physical sciencesElliptic integralQuantum Physics (quant-ph)010306 general physicsHamiltonian (control theory)BifurcationExcitationPhysical Review A
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