20 research outputs found
Disentangling the Electronic and Lattice Contributions to the Dielectric Response of Photoexcited Bismuth
Elucidating the interplay between nuclear and electronic degrees of freedom
that govern the complex dielectric behavior of materials under intense
photoexcitation is essential for tailoring optical properties on demand.
However, conventional transient reflectivity experiments have been unable to
differentiate between real and imaginary components of the dielectric response,
omitting crucial electron-lattice interactions. Utilizing thin film
interference we unambiguously determined the photoinduced change in complex
dielectric function in the Peierls semimetal bismuth and examined its
dependence on the excitation density and nuclear motion of the A phonon.
Our modeled transient reflectivity data reveals a progressive broadening and
redshift of Lorentz oscillators with increasing excitation density and
underscores the importance of both, electronic and nuclear coordinates in the
renormalization of interband transitions.Comment: Manuscript (6 pages) plus supplemental material (6 pages
Supplemental materials for: A miniature high-vacuum valve
The drawings and 3D CADs are shown here. Adobe Acrobat Reader® is recommended for viewing the 3D CADs. All components were generated using SOLIDWORKS® 2013-2014 Education Edition and are illustrated here for instructional purposes only
High-Resolution Bulgeless Liquid-Cell Electron Microscopy
Liquid cell electron microscopy (LCEM) has long suffered from irreproducibility and its inability to confer high-quality images over a wide field of view. LCEM demands the encapsulation of the in-liquid sample between two ultrathin membranes (windows). In the vacuum environment of the electron microscope, the windows bulge, drastically reducing the achievable resolution and the usable viewing region. Herein, we introduce a shape-engineered nanofluidic cell architecture and an air-free drop-casting sample loading technique, which combined, provide robust bulgeless imaging conditions. We demonstrate the capabilities of our approach through the study of in-liquid model samples and quantitative measurements of the liquid layer thickness. The presented LCEM method confers high throughput, lattice resolution across the complete viewing window, and sufficient contrast for the observation of unstained liposomes, paving the way to high-resolution movies of biospecimens in their near native environment