Trichromatic shaper-based quantum state holography

We present an ultrafast quantum state holography scheme based on the interference of photoelectron wave packets from multiphoton ionization (MPI) using shaper-generated trichromatic pulse sequences. By superimposing a probe and a reference electron wave packet generated by MPI with a pump-probe-reference triple-pulse sequence, the phases from the MPI dynamics are imprinted into the resulting photoelectron hologram. In the experiment, we combine white-light supercontinuum pulse shaping with differential photoelectron detection using a velocity-map-imaging spectrometer. To illustrate the holographic scheme, we study the interference of a probe wave packet from (2+1) resonance-enhanced MPI of potassium atoms via the 3d state with a reference wave packet from nonresonant three-photon MPI of its 4s ground state. Phase control of the hologram is exerted by variation of the relative phases of the individual pulses in the sequence. We analyze the hologram to determine the time- and energy-dependent quantum phases resulting from either the free time evolution of the probe wave packet or the detuning of the pump pulse with respect to the resonance and the ensuing time evolution in the excited state of the atom. Our results show that the trichromatic shaper-based photoelectron holography scheme is a powerful tool for time-resolved and phase-sensitive background-free observation of ultrafast quantum dynamics.

Automated summary

An ultrafast quantum state holography scheme based on the interference of photoelectron wave packets from multiphoton ionization was presented, utilizing trichromatic pulse sequences generated by a shaper. The hologram phase control is achieved by varying the relative phases of individual pulses in the sequence. This trichromatic shaper-based photoelectron holography scheme proves to be a powerful tool for time-resolved and phase-sensitive observation of ultrafast quantum dynamics, showing promising results in quantum phase analysis.