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We theoretically analyse the hybrid Mie-exciton optical modes arising from the strong coupling of excitons in organic dyes or transition-metal dichalcogenides with the Mie resonances of high-index dielectric nanoparticles. Detailed analytic…

Mesoscale and Nanoscale Physics · Physics 2018-10-29 C. Tserkezis , P. A. D. Gonçalves , C. Wolff , F. Todisco , K. Busch , N. A. Mortensen

Excitons play major roles in optical processes in modern semiconductors, such as single-wall carbon nanotubes (SWCNTs), transition metal dichalcogenides, and 2D perovskite quantum wells. They possess extremely large binding energies…

Room-temperature single-photon emission (SPE) resulting from a biexciton-exciton cascaded decay is demonstrated for the first time from chemically and photoelectrochemically etched site-controlled In0.14Ga0.86N quantum dots (QDs) embedded…

Mesoscale and Nanoscale Physics · Physics 2026-05-01 Pratim K. Saha

Amorphous silicon films prepared by electron beam evaporation have systematically and substantially greater atomic density for higher thickness, higher growth temperature, and slower deposition rate, reaching the density of crystalline Si…

Materials Science · Physics 2022-04-27 H. C. Jacks , M. Molina-Ruiz , M. H. Weber , J. J. Maldonis , P. M. Voyles , T. H. Metcalf , X. Liu , F. Hellman

The effect of carrier multiplication (CM) in semiconductor nanocrystals is systematically treated by employing an exciton scattering approach. Using projection operators, we reduce the Coulomb coupled multi-exciton dynamics to scattering…

Mesoscale and Nanoscale Physics · Physics 2010-08-31 Andrei Piryatinski , Kirill A. Velizhanin

Squeezing bubbles and impurities out of interlayer spaces by applying force through a few-layer graphene capping layer leads to van der Waals heterostructures with ultra-flat structure free from random electrostatic potential arising from…

Mesoscale and Nanoscale Physics · Physics 2020-12-29 T. Hotta , A. Ueda , S. Higuchi , M. Okada , T. Shimizu , T. Kubo , K. Ueno , T. Taniguchi , K. Watanabe , R. Kitaura

Here we demonstrate the efficient photon-pair generation via spontaneous parametric down conversion from a semiconductor metasurface supporting dual quasi-bound states in the continuum (quasi-BICs). In a simple metasurface design composed…

Optics · Physics 2024-04-22 Tingting Liu , Meibao Qin , Siqi Feng , Xu Tu , Tianjing Guo , Feng Wu , Shuyuan Xiao

Long-lived exciton coherences have been recently observed in photosynthetic complexes via ultrafast spectroscopy, opening exciting possibilities for the study and design of coherent exciton transport. Yet, ambiguity in the spectroscopic…

Antiferromagnetic Mn$_{3}$Ge with a non-collinear Kagome structures present exciting prospects for exploring Berry curvature driven anomalous Hall effects (AHE). Despite substantial progress in bulk systems, the synthesis of crystalline…

Mesoscale and Nanoscale Physics · Physics 2025-02-05 Indraneel Sinha , Purba Dutta , Nazma Firdosh , Shreyashi Sinha , Nirmal Ganguli , Sujit Manna

While silicon solar cells dominate global photovoltaic energy production, their continued improvement is hindered by the single junction limit. One potential solution is to use molecular singlet exciton fission to generate two electrons…

The strength of electrostatic interactions (EI) between electrons and holes within semiconductor nanocrystals profoundly impact the performance of their optoelectronic systems, and different optoelectronic devices demand distinct EI…

A formalism for energy-dependent many-body perturbation theory (MBPT), previously indicated in our recent review articles (Lindgren et al., Phys.Rep. 389,161(2004), Can.J.Phys. 83,183(2005)), is developed in more detail. The formalism…

Quantum Physics · Physics 2009-11-13 Ingvar Lindgren , Sten Salomonson , Daniel Hedendahl

The theory of exciton spectrum in multi-shell hexagonal semiconductor nanotube is developed within the effective masses and rectangular potentials approximations using the method of effective potential. It is shown that the exciton binding…

Mesoscale and Nanoscale Physics · Physics 2012-10-09 O. M. Makhanets , V. I. Gutsul , N. R. Tsiupak , O. M. Voitsekhivska

We report first-principles calculations of the effects of quasiparticle self-energy and electron-hole interaction on the optical properties of single-walled BN nanotubes. Excitonic effects are shown to be even more important in BN nanotubes…

Materials Science · Physics 2007-08-23 Cheol-Hwan Park , Catalin D. Spataru , Steven G. Louie

Employing amorphous superconductors, such as Type-II molybdenum silicide (MoSi), instead of crystalline materials significantly simplifies the material deposition and scalable nanoscale prototyping, beneficial for quantum electronic and…

Pseudoscalar mesons can be produced and studied in high-energy electron-nucleus scattering. We review and extend our previous analysis of meson production in the nuclear Coulomb field. The $P\rightarrow \gamma \gamma$ decay rates are most…

Nuclear Theory · Physics 2013-05-30 Göran Fäldt

A recent breakthrough has been achieved by synthesizing monolayer amorphous carbon (MAC), which introduces a material with unique optoelectronic properties. Here, we used ab initio (DFT) molecular dynamics simulations to study silicon and…

We consider a nanostructure consisting of a semiconductor quantum dot coupled to a metal nanoparticle, and show with numerical simulations that the exciton state of the quantum dot can be robustly generated from the ground state even for…

Mesoscale and Nanoscale Physics · Physics 2022-12-27 Dionisis Stefanatos , Athanasios Smponias , Ioannis Thanopulos , Emmanuel Paspalakis

We develop a method for computing self-energy of a biexciton state in a semiconductor nanostructure using many-body perturbation theory (MBPT) based on the density functional theory (DFT) simulation. We compute energies of low-energy…

Mesoscale and Nanoscale Physics · Physics 2020-03-19 Deyan Mihaylov , Andrei Kryjevski

The specific heat of expanded graphite (EG) and EG--multiwalled carbon nanotube (MWCNT) composites (1.0 and 3.0 wt.\% MWCNTs) was measured between 2 and 300~K. The low-temperature heat capacity is dominated by out-of-plane flexural phonons…