We present a first-principles method for the calculation of the polarization-dependent atomic forces resulting from optical excitation in a solid. We calculate the induced force driving the E(g) phonon mode in bismuth immediately after absorption of polarized light. When radiation with polarization perpendicular to the c axis is absorbed, the photoexcited charge density breaks the threefold rotational symmetry, leading to an atomic force component perpendicular to the axis. We calculate the initial excited electronic distribution as a function of photon energy and polarization and find the resulting atomic force components parallel and perpendicular to the axis. The magnitude of the calculated force is in excellent agreement with that derived from recent measurements of the amplitude of E(g) atomic motion and the decay time of several femtoseconds for the driving force.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.114.055502 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Dimensional confinement and superdiffusive rotational motion of uniaxial colloids in the presence of cylindrical obstacles.
J Chem Phys
January 2025
Out of Equilibrium Group, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India.
In biological systems such as cells, the macromolecules, which are anisotropic particles, diffuse in a crowded medium. In the present work, we have studied the diffusion of spheroidal particles diffusing between cylindrical obstacles by varying the density of the obstacles as well as the spheroidal particles. Analytical calculation of the free energy showed that the orientational vector of a single oblate particle will be aligned perpendicular, and a prolate particle will be aligned parallel to the symmetry axis of the cylindrical obstacles in equilibrium.
View Article and Find Full Text PDFSelf-Assembly of Human Fibrinogen into Microclot-Mimicking Antifibrinolytic Amyloid Fibrinogen Particles.
ACS Appl Bio Mater
December 2024
MOE Key Laboratory of Bio-Intelligent Manufacturing, Liaoning Key Laboratory of Molecular Recognition and Imaging, School of Bioengineering, Dalian University of Technology, Dalian 116024, China.
Recent clinical studies have highlighted the presence of microclots in the form of amyloid fibrinogen particles (AFPs) in plasma samples from Long COVID patients. However, the clinical significance of these abnormal, nonfibrillar self-assembly aggregates of human fibrinogen remains debated due to the limited understanding of their structural and biological characteristics. In this study, we present a method for generating mimetic microclots in vitro.
View Article and Find Full Text PDFComparative Evaluation of Crack Propagation During Root Canal Preparation in Primary Molar with Manual Instrumentation, ProTaper Universal and ProTaper Next Rotary File Systems: An Study.
J Dent (Shiraz)
December 2024
Dept. of Pediatric and Preventive Dentistry, Terna Dental College, Phase - II, Sector- 22, Nerul (west), Navi Mumbai, India.
Statement Of The Problem: Root canal preparation with rotary files causes dentinal cracks in root canals of primary teeth affecting their longevity.
Purpose: Nickel-titanium rotary files have been widely used for root canal preparation in primary teeth. The present study compared occurrence of dentinal microcracks in root canals of extracted primary molar teeth prepared using Hedstrom (H) files, ProTaper Universal rotary files, and ProTaper Next rotary file systems.
A morphology of the distal medial femoral surface that should be considered when performing coronal osteotomy in medial closed wedge distal femoral varus osteotomy.
Knee
December 2024
Department of Orthopaedic Surgery, Showa University Fujigaoka Hospital, Yokohama, Kanagawa, Japan.
Aims: The aim of the present study was to evaluate the morphology of the distal medial femoral surface during coronal osteotomy in medial closed wedge distal femoral varus osteotomy (MCWDFO) using plain CT.
Methods: Twenty knees (mean age, 55.3 years) were included.
A retrospective comparison of Coronal Plane Alignment of the Knee.
J Orthop
June 2025
Georgetown University School of Medicine, 3900 Reservoir Rd NW, Washington DC, 20007, USA.
Background: Unicompartmental arthritic degeneration is treated by unicompartmental knee arthroplasties (UKA). The two current standards are mechanical alignment, where knee placement is perpendicular to the leg's mechanical axis and kinematic alignment, that consists of aligning the knee with the angles specific to the patient's innate bone structure. The purpose of this study was to compare knee alignment between mechanical and kinematic UKA.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!