Chirality is a phenomenon with widespread relevance in fundamental physics, material science, chemistry, optics, and spectroscopy. In this work, we show that a free electron can be converted by the field cycles of laser light into a right-handed or left-handed coil of mass and charge. In contrast to phase-vortex beams, our electrons maintained a flat de Broglie wave but obtained their chirality from the shape of their expectation value in space and time.
View Article and Find Full Text PDFUltrafast electron microscopy provides a movie-like access to structural dynamics of materials in space and time, but fundamental atomic motions or electron dynamics are, so far, too quick to be resolved. Here, we report the all-optical control, compression, and characterization of electron pulses in a transmission electron microscope by the single optical cycles of laser-generated terahertz light. This concept provides isolated electron pulses and merges the spatial resolution of a transmission electron microscope with the temporal resolution that is offered by a single cycle of laser light.
View Article and Find Full Text PDFIntroduction: Spinal disorders are amongst the conditions with the highest burden of disease. To limit the increase of healthcare-related costs in the ageing population, the selection of different types of care for patients with spinal disorders should be optimized. The first step is to investigate the characteristics of these patients and the relationship with treatment.
View Article and Find Full Text PDFThe primary step of almost any interaction between light and materials is the electrodynamic response of the electrons to the optical cycles of the impinging light wave on sub-wavelength and sub-cycle dimensions. Understanding and controlling the electromagnetic responses of a material is therefore essential for modern optics and nanophotonics. Although the small de Broglie wavelength of electron beams should allow access to attosecond and ångström dimensions, the time resolution of ultrafast electron microscopy and diffraction has so far been limited to the femtosecond domain, which is insufficient for recording fundamental material responses on the scale of the cycles of light.
View Article and Find Full Text PDFUltrafast transmission changes around the fundamental trion resonance are studied after exciting a p-shell exciton in a negatively charged II-VI quantum dot. The biexcitonic induced absorption reveals quantum beats between hot-trion states at 133 GHz. While interband dephasing is dominated by relaxation of the P-shell hole within 390 fs, trionic coherence remains stored in the spin system for 85 ps due to Pauli blocking of the triplet electron.
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