Berlin 2015 – wissenschaftliches Programm

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SYFL: Symposium Frontiers of Light

SYFL 2: Frontiers of Light (SYFL)

SYFL 2.3: Hauptvortrag

Dienstag, 17. März 2015, 14:50–15:20, H 0105

Science at the Timescale of the Electron: Tabletop Ultrafast X-rays and Applications in Nano and Materials Science — •Margaret Murnane — JILA, University of Colorado, Boulder, CO 80309, USA

Ever since the invention of the laser 50 years ago, scientists have been striving to extend coherent laser-like beams into the soft X-ray region of the spectrum. Very recently, we used tabletop mid-infrared femtosecond lasers to achieve this goal, and create bright high harmonic X-ray beams at wavelengths spanning from the UV to <10Å.[1] The X*ray supercontinua that are generate represent a coherent version of the Rontgen X-ray tube in the soft X-ray region.

X-rays are powerful probes of the nanoworld. They penetrate thick samples and can image small objects with spatial resolution near the wavelength limit. Therefore, using a tabletop setup, we can probe the fastest charge, spin and energy transport processes in materials. Examples include probing the dynamics of the quantum exchange interaction fundamental to magnetic materials; the use of coherent high harmonic beams for tabletop nanoimaging with record resolution; and uncovering the physical limits of energy flow at the nanoscale.

Moreover, the limits of this new light source are not yet known. In exciting recent work in collaboration with Technion, we also demonstrated bright circularly-polarized harmonics and used them to implement X-ray magnetic circular dichroism measurements on a tabletop.

[1] T. Popmintchev et al., Science 336, 1287 (2012). [2] O. Kfir et al., Nature Photoncs, in press (2014).