Kavli Affiliate: Darrell G. Schlom | First 5 Authors: Mohamed Nawwar, Mohamed Nawwar, , , | Summary: This study reports the observation of phonon-drag thermopower polarity reversal in Ba-doped KTaO3 thin films, mediated by electron-phonon Umklapp scattering. Epitaxial films with distinct carrier concentrations (3.7 x 10^20 cm^-3 and 4.9 x 10^19 cm^-3) were grown via […]
Kavli Affiliate: Richard D. Robinson | First 5 Authors: Thomas J. Ugras, Thomas J. Ugras, , , | Summary: Reciprocity, the principle that a system response is identical in the forward path compared to the backward path, is a fundamental concept across physics, from electrical circuits and optics to acoustics and heat conduction. Nonreciprocity arises […]
Kavli Affiliate: Debanjan Chowdhury | First 5 Authors: Xuepeng Wang, Xuepeng Wang, , , | Summary: The study of interacting topological bands with a tunable bandwidth offers a unique platform to study the interplay of intertwined orders and emergent non-electronic excitations. Here we design a time-reversal symmetric and sign-problem-free electronic model with tunable Chern bands […]
Kavli Affiliate: David A. Muller | First 5 Authors: Desheng Ma, Desheng Ma, , , | Summary: Contrast transfer mechanisms for electron scattering have been extensively studied in transmission electron microscopy. Here we revisit H. Rose’s generalized contrast formalism from scattering theory to understand where information is encoded in four-dimensional scanning transmission electron microscopy (4D-STEM) […]
Kavli Affiliate: David A. Muller | First 5 Authors: Christian K. Belardi, Christian K. Belardi, , , | Summary: Multislice electron ptychography (MEP) is an inverse imaging technique that computationally reconstructs the highest-resolution images of atomic crystal structures from diffraction patterns. Available algorithms often solve this inverse problem iteratively but are both time consuming and […]
Kavli Affiliate: Darrell Schlom | First 5 Authors: Arundhati Ghosal, Arundhati Ghosal, , , | Summary: Conventional racetrack memories move information by pushing magnetic domain walls or other spin textures with spin-polarized currents, but the accompanying Joule heating inflates their energy budget and can hamper scaling. Here we present a voltage-controlled, magnetoelectric racetrack in which […]
Kavli Affiliate: David A. Muller | First 5 Authors: Shake Karapetyan, Shake Karapetyan, , , | Summary: To improve transistor density and electronic performance, next-generation semiconductor devices are adopting three-dimensional architectures and feature sizes down to the few-nm regime, which require atomic-scale metrology to identify and resolve performance-limiting fabrication challenges. X-ray methods deliver three-dimensional imaging […]
Kavli Affiliate: Jie Shan | First 5 Authors: Zhongdong Han, Zhongdong Han, , , | Summary: Topological Kondo insulators (TKIs) are topologically protected insulating states induced not by single-particle band inversions, but by the Kondo interaction between itinerant electrons and a lattice of local magnetic moments. Although experiments have suggested the emergence of three-dimensional (3D) […]
Kavli Affiliate: David A. Muller | First 5 Authors: Shannon S. Fender, Shannon S. Fender, , , | Summary: The interplay between symmetry and topology in magnetic materials makes it possible to engineer exotic phases and technologically useful properties. A key requirement for these pursuits is achieving control over local crystallographic and magnetic structure, usually […]
Kavli Affiliate: Grace Xing | First 5 Authors: Eungkyun Kim, Eungkyun Kim, , , | Summary: AlN has the largest bandgap in the wurtzite III-nitride semiconductor family, making it an ideal barrier for a thin GaN channel to achieve strong carrier confinement in field-effect transistors, analogous to silicon-on-insulator technology. Unlike SiO$_2$/Si/SiO$_2$, AlN/GaN/AlN can be grown […]