Localized wavepackets are created in high- n ( n ~ 300) Rydberg atoms which travel in near-circular orbits around the nucleus. Application of carefully tailored electric fields to quasi-1D Rydberg atoms creates coherent superpositions of Stark states with near extreme values of one of the components of the angular momentum. Half-cycle electric field pulses (HCPs) probe the dynamics of the circular states producing signature oscillations in survival probability that correspond to the expected wavepacket evolution. Although these wavepackets slowly dephase and lose their localization, their motion can be followed for several orbits and provides an analog of the original Bohr model, i.e., an electron in circular classical orbit around the nucleus. Measurements of the asymmetry in survival probability with increasing probe strength at different phases of the orbit confirm orbital motion of the wavepacket. Classical trajectory Monte-Carlo simulations (CTMC) agree with experimental results, and provide promising leads for future studies.
We demonstrate the use of a periodic train of half-cycle pulses to maintain strongly-localized wave packets in very-high-n $(n\ensuremath{\sim}300)$ Rydberg atoms that travel in near-circular orbits about the nucleus. This motion can be followed for hundreds of orbital periods and mimics the original Bohr model of the hydrogen atom which envisioned an electron in circular classical orbit about the nucleus.