Excitons play a key role in the linear optical response of two-dimensional (2D) materials. However, their role in the nonlinear response to intense, nonresonant, low-frequency light is often overlooked as strong fields are expected to tear the electron-hole pair apart. Using high-harmonic generation as a spectroscopic tool, we theoretically study their formation and role in the nonlinear optical response. We show that the excitonic contribution is prominent and that excitons remain stable even when the driving laser field surpasses the strength of the Coulomb field binding the electron-hole pair. We demonstrate a parallel between the behavior of strongly laser-driven excitons in 2D solids and strongly driven Rydberg states in atoms, including the mechanisms of their formation and stability. Last, we show how the excitonic contribution can be singled out by encapsulating the 2D material in a dielectric, tuning the excitonic energy and its contribution to the high-harmonic spectrum.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11364094 | PMC |
http://dx.doi.org/10.1126/sciadv.adn6985 | DOI Listing |
J Neurosurg Case Lessons
January 2025
Department of Neurology, Mayo Clinic, Rochester, Minnesota.
Background: Adamantinomatous craniopharyngiomas (ACPs) are slow-growing, cystic, highly morbid central nervous system tumors located adjacent to vital structures including the pituitary, hypothalamus, and optic chiasm. Tumor recurrence is common. Treatment relies on resection with or without adjuvant radiation and is highly individualized.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
School of Materials Science and Engineering, Zhengzhou University, No.100 Science Avenue, Zhengzhou, 450001, P. R. China.
Photoswitchable fluorescent materials have gained significant attention for their potential in advanced information encryption and anti-counterfeiting applications. However, the common use of UV light to trigger the isomerization processes leads to photobleaching and poor fatigue resistance. Visible-light-driven fluorescent photoswitches are highly desirable, but achieving high cyclization yield remains challenging.
View Article and Find Full Text PDFPLoS One
January 2025
Key Laboratory of Clinical Evaluation Technology for Medical Device of Zhejiang Province, Department of Clinical Engineering and Material Supplies, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China.
The structural alterations in the constituent materials of nanocomposites such as graphene nanocomposites typically induce changes in their properties including mechanical, electrical, and optical properties. Therefore, by altering the preparation conditions of nanocomposites and investigating their responsiveness to basic biomolecules (such as proteins), it is possible to explore the application potentials of the composites and guide development of new nanocomposite preparation. In this study, different composites of graphene oxide and gold nanoparticles (AuNPs/GO) were obtained by varying the volumes of reducing agents used in the one-pot hydrothermal method.
View Article and Find Full Text PDFChemphyschem
January 2025
University of Minnesota Twin Cities, Chemical Engineering and Materials Science, 421 Washington Avenue SE, 55455, Minneapolis, UNITED STATES OF AMERICA.
Broader adoption of 4D ultrafast electron microscopy (UEM) for the study of chemical, materials, and quantum systems is being driven by development of new instruments as well as continuous improvement and characterization of existing technologies. Perhaps owing to the still-high barrier to entry, the full range of capabilities of laser-driven 4D UEM instruments has yet to be established, particularly when operated at extremely low beam currents (~fA). Accordingly, with an eye on beam stability, we have conducted particle tracing simulations of unconventional off-axis photoemission geometries in a UEM equipped with a thermionic-emission gun.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
January 2025
Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China.
Purpose: Previous studies have reported divergent sexual responses to aging; however, specific variations in gene expression between aging males and females and their potential association with age-related retinal diseases remain unclear. This study collected data from public databases and developed a comprehensive comparison of retina between aging females and males.
Methods: Single-cell RNA (scRNA) and bulk RNA sequencing data of the aging retina from females and males in public databases were utilized for integrated analysis to investigate sex-biased expression in retina.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!