Kinks near the Fermi level observed in angle-resolved photoemission spectroscopy (ARPES) have been widely accepted to represent electronic coupling to collective excitations, but kinks at higher energies have eluded a unified description. We identify the mechanism leading to such kink features by means of ARPES and tight-binding band calculations on σ bands of graphene, where anomalous kinks at energies as high as ∼4 eV were reported recently [Phys. Rev. Lett. 111, 216806 (2013)]. We found that two σ bands show a strong intensity modulation with abruptly vanishing intensity near the kink features, which is due to sublattice interference. The interference induced local singularity in the matrix element is a critical factor that gives rise to apparent kink features, as confirmed by our spectral simulations without involving any coupling to collective excitations.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.116.186802 | DOI Listing |
J Biomol Struct Dyn
January 2025
College of Applied Medical Sciences, lmam Abdulrahman Bin Faisal University (lAU), Dammam, Saudi Arabia.
The present study explores the conformational dynamics of the membrane protein of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) within the Endoplasmic Reticulum-Golgi Intermediate Compartment (ERGIC) complex using an all-atomistic molecular dynamics simulation approach. Significant structural changes were observed in the N-terminal, C-terminal, transmembrane, and beta-sheet sandwich domains of the MERS-CoV membrane protein. This study also highlights the structural similarities between the MERS-CoV and the SARS-CoV-2 membrane proteins, particularly in how both exhibit a distinct kink in the transmembrane helix caused by aromatic residue-lipid interactions.
View Article and Find Full Text PDFJ Mech Behav Biomed Mater
December 2024
Department of Biomedical Engineering, The University of Utah, 36 S Wasatch Dr, Salt Lake City, UT, 84112, USA; Department of Biomedical Engineering, Texas A&M University, 101 Bizzell St, College Station, TX, 77843, USA; Scientific Computing and Imaging Institute, The University of Utah, 72 Central Campus Dr, Salt Lake City, UT, 84112, USA; School of Engineering Medicine, Texas A&M University, 1020 Holcombe Blvd., Houston, TX, 77030, USA; Department of Multidisciplinary Engineering, Texas A&M University, 101 Bizzell St, College Station, TX, 77843, USA; Department of Cardiovascular Sciences, Houston Methodist Academic Institute, 6565 Fannin Street, Houston, TX, 77030, USA. Electronic address:
The failure of synthetic small-diameter vascular grafts has been attributed to a mismatch in the compliance between the graft and native artery, driving mechanisms that promote thrombosis and neointimal hyperplasia. Additionally, the buckling of grafts results in large deformations that can lead to device failure. Although design features can be added to lessen the buckling potential (e.
View Article and Find Full Text PDFPNAS Nexus
December 2024
Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
Ferroelectric nematic (N) liquid crystals present a compelling platform for exploring topological defects in polar fields, while their structural properties can be significantly altered by ionic doping. In this study, we demonstrate that doping the ferroelectric nematic material RM734 with cationic polymers enables the formation of polymeric micelles that connect pairs of half-integer topological defects. Polarizing optical microscopy reveals that these string defects exhibit butterfly textures, featured with a 2D polarization field divided by Néel-type kink walls into domains exhibiting either uniform polarization or negative splay and bend deformations.
View Article and Find Full Text PDFHeliyon
November 2024
Laboratory of Research on Advanced Materials and Nonlinear Sciences, Department of Physics, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.
In the present work, we focus on the longitudinal model of microtubules (MTs) proposed by Satarić et al. (1993) [12], and that considers MT cells to have ferroelectric properties (behaviors) due to dipolar oscillations of dimers within MTs, i.e.
View Article and Find Full Text PDFValley kink states and valley-polarized chiral edge states, whose topologically protected one-way propagation property provides a promising solution for manipulating light waves, have recently attracted considerable attention in topological photonics. However, it remains a great challenge to realize flexibly tunable dispersion for two different topological states and to develop a dynamically controllable topological photonic platform for switching topological wave routing. In this work, we propose a reconfigurable topological wave routing structure in the telecommunication frequency range, where phase-change material SbS cylinders with tunable refractive index are embedded into each topological channel to dynamically tune the dispersion of topological edge states.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!