Journal of Optics B Quantum and Semiclassical Optics
On decoherence and nonlinear effects in the generation of quantum states of motion in Paul traps
Rocío Jáuregui, J. Récamier, Pedro Antonio Quinto-Su
Abstract
We study some possible sources of decoherence in the generation of nonclassical states of motion of ions in Paul traps by means of numerical simulations based on reported experiments. In particular we study the consequences of the spontaneous decay of the internal energy state |0⟩ i which couples the two hyperfine internal states |1⟩ i and |2⟩ i in the two-photon Raman transitions used to manipulate the ion motional state. We also consider some possible experimental limitations to generate coherent states due to nonlinear effects in the coupling of the centre-of-mass coordinates with the laser field. A similar analysis is performed for carrier pulses taking into account nonlinearities and micromotion. The quantum evolution of the ion internal and centre-of-mass degrees of freedom are studied using amplitude equations derived from Schrödinger's equation. The limitations of such an approach are also discussed.