We argue that the vacuum polarization by the virtual electron-positron pairs can be measured by studying a Josephson junction in a strong magnetic field. The vacuum polarization results in a weak dependence of the Josephson constant on the magnetic field strength which is within the reach of the existing experimental techniques.
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http://dx.doi.org/10.1103/PhysRevLett.104.097003 | DOI Listing |
Phys Rev Lett
December 2024
Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Distinguishing whether a system supports alternate low-energy (locally stable) states-stable (true vacuum) versus metastable (false vacuum)-by direct observation can be difficult when the lifetime of the state is very long but otherwise unknown. Here we demonstrate, in a tractable model system, that there are physical phenomena on much shorter timescales that can diagnose the difference. Specifically, we study the time evolution of the magnetization following a quench in the tilted quantum Ising model, and show that its magnitude spectrum is an effective diagnostic.
View Article and Find Full Text PDFPhytochem Anal
December 2024
Department of Chemistry, Colorado State University, Fort Collins, Colorado, USA.
Introduction: Phenolic compounds garner interest in developing medicines, nutraceuticals, and cosmeceuticals based on natural products. The quantity of phenolic compounds in a sample is commonly determined via spectrophotometry; however, this instrumented technique is relatively laborious and time consuming and requires a large amount of reagents.
Objective: This work aimed to develop a simple, point-of-need colorimetric sensor to rapidly determine total phenolic content (TPC) in tea extracts.
Nanotechnology
January 2025
University Lille, CNRS, University Polytechnique Hauts-de-France, UMR 8520-IEMN-Institut d'Electronique de Microélectronique et de Nanotechnologie, F-59000 Lille, France.
We report here the reversibility and bistability of the switching behavior in an azobenzene derivative induced by the bias applied by a scanning-tunneling microscopy (STM) tip, at low temperature and in ultra-high vacuum environment. Thisto-andto-switching were observed during STM imaging in either polarity at +2 V or -2 V, on a sub-second time scale. This results in a blinking effect visible on STM images, corresponding to the reversible switching of the azobenzene molecule under the applied STM bias through an electric field induced process.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Besides the intensity and wavelength, the ability to analyze the optical polarization of detected light can provide a new degree of freedom for numerous applications, such as object recognition, biomedical applications, environmental monitoring, and remote sensing imaging. However, conventional filter-integrated polarimetric sensing systems require complex optical components and a complicated fabrication process, severely limiting their on-chip miniaturization and functionalities. Herein, the reconfigurable polarimetric photodetection with photovoltaic mode is developed based on a few-layer MoS/PdSe heterostructure channel and a charge-trap structure composed of AlO/HfO/AlO (AHA)-stacked dielectrics.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Faculty of Chemistry and Food Chemistry, TU Dresden, Bergstrasse 66c, 01069 Dresden, Germany.
ConspectusTriangulene (TRI) and its heterotriangulene (HT) derivatives are planar, triangle-shaped molecules that, via suitable coupling reactions, can form extended organic two-dimensional (2D) crystal (O2DC) structures. While TRI is a diradical, HTs are either closed-shell molecules or monoradicals which can be stabilized in their cationic form.Triangulene-based O2DCs have a characteristic honeycomb-kagome lattice.
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