Regensburg 2019 – wissenschaftliches Programm
O 3.5: Vortrag
Montag, 1. April 2019, 11:30–11:45, H5
Single switching events of one molecule observed by femtosecond STM — •Dominik Peller, Thomas Buchner, Lukas Kastner, Rupert Huber, and Jascha Repp — University of Regensburg, 93040 Regensburg, Germany
Using THz waves to control electrons in a scanning tunneling microscope (STM) has opened the door to ultrafast atomic-scale microscopy. Recently, we combined low-temperature STM with ultrafast single-electron lightwave electronics to push microscopy to the ultimate spatio-temporal quantum limit via a novel state-selective tunneling regime . The peak of a THz electric-field waveform transiently opens an otherwise forbidden tunneling channel through a single molecular orbital. This process allows us to record the first-ever ∼100 fs sub-Å snapshot images of a single molecule’s orbitals and the first femtosecond movie of a single vibrating molecule.
Here, we introduce single-shot detection in lightwave STM as the first approach resolving individual unidirectional quantum events on simultaneous atomic and femtosecond scales. We trigger switching of an individual molecule by single-electron injection and detect every event in real time. Analyzing the quantum statistics of the different reaction paths separately, electron by electron, we time-resolve the molecule’s ultrafast, statistical motion along its reaction coordinate.
Moreover, this process allows us to measure a THz near-field waveform within a subatomic volume directly in the time domain.
 T. L. Cocker, D. Peller et al., Nature 539, 263-267 (2016)