Relative Phase Measurement of a Stark Wave Packet in the Vicinity of the Saddle Point

Abstract

A gas of Rb atoms in a static electric field has been photoexcited to just above the classical ionization threshold by a phase-locked sequence of two far infrared pulses. A single laser pulse generates a series of ejected electron packets emerging at the saddle point of the potential; each of the ejected packets is characterized by a phase and a chirp. We calculate and measure these phases and chirps using the time dependent interference of the electronic wave function controlled by the delay between the two light pulses.

Manipulating electron wave packets

“…Recently, Rella et al (2000) measured the phase of a wave packet in a static electric ® eld at the saddle point as the electron was ejected from the atomic potential. Upon ejection of the wave packets, the properties remain unchanged as they are accelerated in the ® eld.…”