We present a theoretical framework for the evolution of the internal state of a fast highly charged one-electron ion traversing an amorphous solid. We employ an open quantum system approach which incorporates the complex array of collisions with electrons and ionic cores in the solid within the framework of system-reservoir interactions. Interactions with the solid environment and the radiation field are treated on the same footing and the quantum master equation for the reduced density matrix of the electronic state of the ion is approximated by a Lindblad equation. The latter allows the solution of this multistate problem in terms of Monte Carlo sampling of quantum trajectories. Similarities and extensions to methods used in quantum optics and previously employed in ion-solid interactions are discussed. Our focus is on the transient buildup and destruction of coherences by stochastic processes. We apply our method to the study of coherence properties of the internal state of a fast ${\mathrm{Kr}}^{35+}$ ion traversing carbon foils. Simulations exhibit clear signatures of partially coherent transitions and are found to be in good agreement with experimental data.We present a theoretical framework for the evolution of the internal state of a fast highly charged one-electron ion traversing an amorphous solid. We employ an open quantum system approach which incorporates the complex array of collisions with electrons and ionic cores in the solid within the framework of system-reservoir interactions. Interactions with the solid environment and the radiation field are treated on the same footing and the quantum master equation for the reduced density matrix of the electronic state of the ion is approximated by a Lindblad equation. The latter allows the solution of this multistate problem in terms of Monte Carlo sampling of quantum trajectories. Similarities and extensions to methods used in quantum optics and previously employed in ion-solid interactions are discussed. Our focus is on the transient buildup and destruction of coherences by stochastic processes. We apply our method to the study of coherence properties of the internal state of a fast ${\mathrm{Kr}}^{35+}$ ion traversing carbon foils. Simulations exhibit clear signatures of partially coherent transitions and are found to be in good agreement with experimental data.

Physical Review AFeb 28, 200325 citations

Theory of optical phase conjugation in coupled ion pairs

Juan Francisco Lam

Coupled ion pairs in solids have played an important role in the development of new solid-state lasers. The long-range interaction among two or more ions provides a channel for the inversion of population, leading to the discovery of new emission lines. Because of the relatively large optical cross sections, coupled ion pairs may provide new media for the implementation of a solid-state phase conjugate mirror. We present a theory of optical phase conjugation via four-wave mixing in such novel materials. For a model ion-doped solid-state system, the calculations give the following conclusions. First, the spectral linewidth is proportional to the square root of the intensity of the radiation field in an inhomogenously broadened material for fixed ion density. Second, the linewidth decreases with increasing ion density for the fixed intensity level. And last, the saturation intensity also decreases with increasing ion density for the fixed optical intensity. The behavior of the linewidth and the saturation intensity are attributed to the strong interaction among two nearest-neighbor ion pairs, which leads to the generation of additional energy dumping pathways.Coupled ion pairs in solids have played an important role in the development of new solid-state lasers. The long-range interaction among two or more ions provides a channel for the inversion of population, leading to the discovery of new emission lines. Because of the relatively large optical cross sections, coupled ion pairs may provide new media for the implementation of a solid-state phase conjugate mirror. We present a theory of optical phase conjugation via four-wave mixing in such novel materials. For a model ion-doped solid-state system, the calculations give the following conclusions. First, the spectral linewidth is proportional to the square root of the intensity of the radiation field in an inhomogenously broadened material for fixed ion density. Second, the linewidth decreases with increasing ion density for the fixed intensity level. And last, the saturation intensity also decreases with increasing ion density for the fixed optical intensity. The behavior of the linewidth and the saturation intensity are attributed to the strong interaction among two nearest-neighbor ion pairs, which leads to the generation of additional energy dumping pathways.

Annual Meeting Optical Society of AmericaJan 1, 19880 citations

Interaction of Radiation with Atoms

Daniel F. Walls, Gerard J Milburn

Graduate texts in physicsJan 1, 20250 citations

{\mathrm{Kr}}^{35+}

ion traversing carbon foils. Simulations exhibit clear signatures of partially coherent transitions and are found to be in good agreement with experimental data.