Quantumness “Under the Hood” of Ultrafast Nanoscopy in Lensless Imaging Using HHG and in Electron Microscopy
December 14th, 2021 OFER KFIR Tel- Aviv University

In the pursuit of ever-better technologies, it could be beneficial to look back on developed techniques and investigate the fundamental physical mechanisms that underpin their merit. This talk will detail two seemingly well-understood tools for observing ultrafast dynamics at the nanoscale: electron microscopes and lensless imaging with high harmonic generation (HHG). In electron microscopy, I will discuss the prospect of optically dressing the wave-function of electrons in the beam. Thus, the electron beam can transfer optical coherence in a vacuum with sub-nanometer precision, down to an individual quantum system. I will focus on one particular outcome, cathodoluminescence (CL), discussing how such a novel mutual coherence with a reference laser opens a path for quantum state tomographic techniques through homodyne mixing. For lensless imaging with soft-X-rays, the talk will present a decade-long paradigm of the community considering the information limit, expressed as the signal-to-noise ratio (SNR), and how the understanding of quantum properties of the radiation field can overcome it. I will show some of the high-quality reconstructed images this concept enables, acquired with circularly polarized HHG beams. Our sub-wavelength-resolution images from challenging low-scattering samples such as magnetic domains surpass results from even from large-scale facilities as Synchrotrons and Free-electron lasers (FELs) that use a 10-fold shorter wavelength.

Tuesday, December 14, 2021, 12:00. Seminar Room

Hosted by Prof Javier Garcia de Abajo