Interfering Rydberg wave packets in Na

Abstract

This paper presents an experimental and theoretical analysis of quantum interference between Rydberg wave packets in Na. Pairs of phase-locked wave packets manipulate the total orbital angular momentum of Na Rydberg atoms. Initially, the wave packet is composed of a superposition of s and d Rydberg series. Exploitation of the difference between the quantum defects of the two series allows one to predict the phase of the second wave packet required to engineer specific angular momentum compositions within the resultant wave packet. Experimentally, this final quantum state distribution is analysed in the frequency domain using state-selective field ionization and in the time domain using the optical Ramsey method. The theoretical calculations show how the phase difference between pairs of optical pulses is linked to the corresponding Rydberg frequency spectrum, therefore enabling the control of the quantum state composition of the wave packets. Finally, it is shown that by intuitively chirping one of the laser pulses it is possible to compensate for the dispersion of the wave packet and improve the effectiveness of the angular momentum control.