NONDISPERSING RADIAL RYDBERG WAVEPACKETS IN DOUBLY CORE-DRIVEN 2-ELECTRON ATOMS

We consider a two-electron Rydberg atom, whose core is driven by two l aser fields in a lambda configuration. The two laser pulses are near r esonant to the corresponding transitions but are slightly and equally detuned from the upper level. In the case of sufficiently large detuni ng, spontaneous emission is negligible in this context. We show that s lowly decaying but nondispersing radial Rydberg wavepackets, involving arbitrarily large principal quantum numbers, can be prepared in this system without being affected by spontaneous emission. Ca has the prop erties required for this effect and is employed as a realistic model i n this paper.