Quantum interference visibility spectroscopy in two-color photoemission from tungsten needle tips

Abstract

When two-color femtosecond laser pulses interact with matter, electrons can be emitted through various multiphoton excitation pathways. Quantum interference between these pathways gives rise to a strong oscillation of the photoemitted electron current, experimentally characterized by its visibility. In this work, we demonstrate two-color visibility spectroscopy of multi-photon photoemission from a solid-state nanoemitter. We investigate the quantum pathway interference visibility over an almost octave-spanning wavelength range of the fundamental femtosecond laser pulses and their second-harmonic. The photoemission shows a high visibility of 90% +/- 5%, with a remarkably constant distribution. Furthermore, by varying the relative intensity ratio of the two colors, we find that we can vary the visibility between 0 and close to 100%. A simple but highly insightful theoretical model allows us to explain all observations, with excellent quantitative agreements. We expect this work to be universal to all kinds of photo-driven quantum interference, including quantum control in physics, chemistry and quantum engineering.

References in corpus (5)

• Making ultracold molecules in a two color pump-dump photoassociation scheme using chirped pulses
• Two-color coherent control of femtosecond above-threshold photoemission from a tungsten nanotip
• Large optical field enhancement for nanotips with large opening angles
• High Visibility in Two-Color Above-Threshold Photoemission from Tungsten Nanotips in a Coherent Control Scheme
• Two-color Multiphoton Emission from Nanotips

Cited by in corpus (4)

• Two-color coherent control in photoemission from gold needle tips
• Attosecond control of solid-state high harmonic generation using ω-3ω fields
• Momentum space separation of quantum path interferences between photons and surface plasmon polaritons in nonlinear photoemission microscopy
• Ultrafast optically induced tunneling in narrow metallic gaps from the time dependent density functional perspective