Resonant Excitation Rate Research Articles

Anomalous Broadening in Driven Dissipative Rydberg Systems.

We observe interaction-induced broadening of the two-photon 5s-18s transition in ^{87}Rb atoms trapped in a 3D optical lattice. The measured linewidth increases by nearly 2 orders of magnitude with increasing atomic density and excitation strength, with corresponding suppression of resonant scattering and enhancement of off-resonant scattering. We attribute the increased linewidth to resonant dipole-dipole interactions of 18s atoms with blackbody induced population in nearby np states. Over a range of initial atomic densities and excitation strengths, the transition width is described by a single function of the steady-state density of Rydberg atoms, and the observed resonant excitation rate corresponds to that of a two-level system with the measured, rather than natural, linewidth. The broadening mechanism observed here is likely to have negative implications for many proposals with coherently interacting Rydberg atoms.

Resonance excitation process for Ni-like gold

A detailed and large-scale calculation on the resonant excitation rate coefficients from the ground state to the 106 fine-structure levels belonging to 3 l 17 4 l ′ ( l = 0 , 1 , 2 ; l ′ = 0 , 1 , 2 , 3 ) configurations of Ni-like gold have been performed using the relativistic distorted-wave approximation. The contributions through all possible Cu-like doubly excited states 3 l 17 4 l ′ n ″ l ″ and 3 l 17 5 l ′ n ″ l ″ ( n ″ ≤ 15 , l ″ ≤ 8 ) are calculated explicitly. The radiative damping effects on resonant excitation rates are studied. Significant effects arising from decays to autoionizing levels are also investigated. The n −3scaling law is investigated and is used to obtain the contributions from high- n configurations. Contributions from resonant excitation are found to be as important as direct excitation processes for most transitions. In some cases, resonant excitation can enhance the excitation rate coefficients by an order of magnitude. In addition, the total dielectronic recombination rate coefficients of Ni-like gold are also presented and compared with other works.

Resonance-excitation process for Ni-like tantalum

A detailed large-scale calculation on the resonant excitation rate coefficients from the ground state to the 106 fine-structure levels belonging to $3{l}^{17}4{l}^{\ensuremath{'}}$ ($l=0,1,2$; ${l}^{\ensuremath{'}}=0,1,2,3$) configurations of Ni-like tantalum have been performed using the relativistic distorted-wave approximation. The contributions through all possible Cu-like doubly excited states $3{l}^{17}4{l}^{\ensuremath{'}}{n}^{\ensuremath{''}}{l}^{\ensuremath{''}}$ and $3{l}^{17}5{l}^{\ensuremath{'}}{n}^{\ensuremath{''}}{l}^{\ensuremath{''}}$ (${n}^{\ensuremath{''}}\ensuremath{\leqslant}15$, ${l}^{\ensuremath{''}}\ensuremath{\leqslant}8$) are calculated. The validity of ${n}^{\ensuremath{''}\ensuremath{-}3}$ scaling law is investigated. The radiative damping effects on resonant excitation rates are studied. The significant effects arising from decays to autoionizing levels are also investigated. The contributions from resonant excitation are found to be as important as direct excitation processes for most transitions. In some cases, the resonant excitation can enhance the excitation rate coefficients by an order of magnitude. Large discrepancies between the present resonant excitation rate coefficients with previously published values are found, and the present results should be more reliable and accurate.

Resonance excitation rate coefficients of Ni-like tungsten

A detailed and large-scale calculation on the resonant excitation rate coefficients from the ground state to the 106 fine-structure levels belonging to 3l174l′(l = 0, 1, 2; l′ = 0, 1, 2, 3) configurations of Ni-like tungsten has been performed using the relativistic distorted-wave method. The contributions through all possible Cu-like doubly excited states 3l174l′nl″ and 3l175l′nl″(n ⩽ 15, l″ ⩽ 8) are calculated explicitly. The n−3 scaling law is investigated and is used to obtain the contributions from high-n configurations. The radiative damping effects on resonant excitation rates are studied. The effects arising from the inclusion of decays to autoionizing levels are also investigated. The contributions from resonant excitation are found to be as important as the direct-excitation processes for most transitions. In some cases, the resonant excitation can enhance the excitation rate coefficients by a factor of an order of magnitude. Because all possible resonances associated with the ▵n = 1 and ▵n = 2 core excitations and the effects of decays into autoionizing levels from the resonant states are taken into account, large discrepancies between the present excitation rate coefficients and R-matrix values are found.

Resonant excitations of high energy nuclei in aligned crystal targets

Resonant transitions to excited nuclear states are predicted when relativistic nuclei are directed along a crystal axis. The periodic field of the crystal can be treated as a flux of photons; therefore, this process is analogous to photo-excitation. Resonance occurs when the velocity of the nucleus and the periodicity of the lattice lead to a field at the nucleus whose frequency corresponds to a nuclear excitation frequency. Calculations predict a resonant excitation rate which, although not large, may be observable.