arXiv subjects

Gengyue Dong

Publications and source records attributed to Gengyue Dong.

2 recordsLinked to original sources

arXiv2025

Atomistic Theory of Plasmon-Induced Hot-carriers in Al Nanoparticles

Hot electrons and holes generated from the decay of localized surface plasmons (LSPs) in aluminum nanostructures have significant potential for applications in photocatalysis, photodetection and other optoelectronic devices. Here, we present a theoretical study of hot-carrier generation in aluminum nanospheres using a recently developed modelling approach that combines a solution of the macroscopic Maxwell equation with large-scale atomistic tight-binding simulations. Different from standard plasmonic metals, such as gold or silver, we find that the energetic distribution of hot electrons and holes in aluminium nanoparticles is almost constant for all allowed energies. Only at relatively high photon energies, a reduction of the generation rate of highly energetic holes and electrons close to the Fermi level is observed which is attributed to band structure effects suppressing interband decay channels. We also investigate the dependence of hot-carrier properties on the nanoparticle diameter and the environment dielectric constant. The insights from our study can inform experimental efforts towards highly efficient aluminum-based hot-carrier devices.

physics.optics↗

arXiv2025

The Strain Impact on Weyl Semimetals

Weyl semimetals are a class of topological semimetals defined by a Chern number as their topological invariant. These materials exhibit unique properties, such as transverse topological currents and anomalous magnetoelectric responses, making them promising candidates for device applications.This thesis explores the effects of strain on the electronic properties of Weyl semimetals using both toy models and first-principles calculations, specifically density functional theory (DFT) combined with the Wannier method. We investigated the strain effects on two-band tight-binding toy models by tuning their hopping integrals. To connect these models to real materials, we derived a tight-binding Hamiltonian from DFT combined with Wannier functions and analyzed the surface states and density of states under varying strain conditions. Our results reveal that both tensile and compressive strains significantly alter the electronic structure of TaAs, potentially inducing topological phase transitions. Specifically, tensile strain along the [100] direction leads to the transformation and eventual disappearance of Fermi arcs, while compressive strain results in the formation of complex surface states, suggesting the emergence of a new phase at higher strain levels.

cond-mat.mtrl-sci↗