Scenes from the JRM Lab

Scenes from the JRM Lab

Scenes from the JRM Lab

Scenes from the JRM Lab

Scenes from the JRM Lab


Charge Migration

K-State University Distinguished Professor Chii-Dong Lin, together with collaborators from Huazhong University and the University of Connecticut, recently proposed a high harmonic spectroscopy (HHS) method for measuring the charge migration (CM) speed in a carbon-chain molecule, butadiyne (C4H2). The principle of HHS is based on the three-step model of high-order harmonic generation (HHG): ionization, acceleration, and recombination. Strong field ionization first creates a hole wave packet in the ion, which evolves in the laser field and is probed by the returning electron wave packet at the recombination moment, with the hole dynamics recorded in the generated harmonic spectra. The researchers used a two-color HHS scheme in combination with an advanced machine learning reconstruction algorithm to reconstruct the CM in C4H2 at the most fundamental level for each single fixed-in-space angle of the molecule. The method achieved a temporal resolution of 50 as. From analyzing the experimental results, they found that the charge migration speed ranges from 4.5 Å/fs to 2.9 Å/fs, for molecules oriented from parallel to perpendicular to the laser field direction. Here Å/fs ( Angstrom / femtosecond) is 100 km/s. For comparison, the speed of an Olympian sprinter is about 0.1 km/s.

This work was reported in the SPIE journal Advanced Photonics in August 2023 and in a SPIE press release, on which this description is based.


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This Week at JRM

Week of 24 September 2023

Mon1:30 pm Nuts & Bolts
News & status (Hybrid, CW119)
 4:30 pm Colloquium
D. Rolles, KSU (Hybrid, CW102)
Wed1:30 pm AMO Seminar
Renner & Shi, KSU (CW144/145)
ThuAll Day Fall Gathering
Faculty & Staff (CW119)

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What's New?

The JRM Lab is featured in a recent issue of K-State's research magazine, "Seek". The article, "Laser Focus", highlights our work in ultrafast AMO physics and our many collaborations.

Seek combines a variety of written content with creative photography and innovative design to tell the stories of university researchers.

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