Massless Dirac particles cannot be confined by an electrostatic potential. This is a problem for making graphene quantum dots but confinement can be achieved with a magnetic field and here general conditions for confined and deconfined states are derived. There is a class of potentials for which the character of the state can be controlled at will. Then a confinement-deconfinement transition occurs which allows the Klein paradox to be probed experimentally in graphene dots. A dot design suitable for this experiment is presented.
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http://dx.doi.org/10.1088/0953-8984/21/10/102201 | DOI Listing |
Commun Med (Lond)
January 2025
Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Background: High-field magnetic resonance imaging (MRI) is a powerful diagnostic tool but can induce unintended physiological effects, such as nystagmus and dizziness, potentially compromising the comfort and safety of individuals undergoing imaging. These effects likely result from the Lorentz force, which arises from the interaction between the MRI's static magnetic field and electrical currents in the inner ear. Yet, the Lorentz force hypothesis fails to explain observed eye movement patterns in healthy adults fully.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Applied Physics and Chemical Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan.
We report the synthesis, crystal structure, and magnetic properties of a new Kitaev honeycomb cobaltate, KCoAsO, which crystallizes in two distinct forms: P2/c and R[Formula: see text] space groups. Magnetic measurements reveal ordering temperatures of ~ 14 K for the P2/c structure and ~ 10.5 K for the R[Formula: see text] structure.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Hubei Longzhong Laboratory, Wuhan University of Technology, Xiangyang Demonstration Zone, Xiangyang 441000, China.
Materials with both high thermoelectric (TE) performance and excellent magnetocaloric (MC) properties near room temperature are of great importance for all-solid-state TE/MC hybrid refrigeration. A combination of such two critical characteristics, however, is hardly attainable in single phase compounds. Herein we report a composite material that comprises Bi-Sb-Te thermoelectric and Ni-Mn-In magnetocaloric components as an innovative thermoelectromagnetic material with dual functionalities.
View Article and Find Full Text PDFBiosens Bioelectron
January 2025
College of Mathematical Medicine, Zhejiang Normal University, Jinhua, China; Affiliated Dongyang Hospital of Wenzhou Medical University, Jinhua, China. Electronic address:
Pathological conditions in organisms often arise from various cellular or tissue abnormalities, including dysregulation of cell numbers, infections, aberrant differentiation, and tissue pathologies such as lung tumors and skin tumors. Thus, developing methods for analyzing and identifying these biological abnormalities presents a significant challenge. While traditional bioanalytical methods such as flow cytometry and magnetic resonance imaging are well-established, they suffer from inefficiencies, high costs, complexity, and potential hazards.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2025
Institute of Intelligent Machines, Hefei Institute of Intelligent Agriculture, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; Science Island Branch of Graduate School, University of Science & Technology of China, Hefei 230026, China. Electronic address:
The out-of-plane (OOP) deformations of metalloporphyrins macrocycle are closely related to their biological functions, and Raman spectroscopy is a powerful tool for investigating OOP deformations. However, due to the interplay of electronic structure, substituents, porphyrin macrocycle in-plane (IP) and OOP deformations, it is challenging to measure the OOP deformations directly, or, establish a confirmative correlation between the frequency shifts of characteristic peaks and specific OOP deformation changes. In this work, we first selected the model porphyrin Ni-P and employed DFT calculations to explore the relationship between the ruffling and saddling deformation changes and their corresponding Raman spectral differences.
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