We use scanning tunneling microscope break-junction (STM-BJ) measurements to study the low-bias conductance and high-bias current-voltage (IV) characteristics of a series of asymmetric para-meta connected diphenyl-oligoenes. From tight-binding calculations, we determine that the quantum interference features inherent in our molecular design result in a 'through-bond' coupling on the para-side, and through-space coupling on the meta-side. We show that these molecular junctions form single molecule diodes, and show that the rectification results from a difference in the voltage dependence of the coupling strength on the through-bond and the through-space side. The interplay between the applied voltage and the molecule-metal coupling results from the asymmetric polarizability of the conducting orbital under an external field.
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http://dx.doi.org/10.1039/c4fd00093e | DOI Listing |
Phys Rev Lett
February 2025
University of Ottawa, Department of Physics and Nexus for Quantum Technologies, 25 Templeton Street, Ottawa, Ontario, Canada K1N 6N5.
We introduce an ultrasensitive interferometric protocol that combines weak value amplification (WVA) with traditional interferometry. This protocol WVA+interferometry uses weak value amplification of the relative delay between two paths to enhance interferometric sensitivity. As an example, we demonstrate a proof-of-principle experiment that achieves few-attosecond timing resolution (few nanometer path length resolution) with a double-slit interferometer using only common optical components.
View Article and Find Full Text PDFSci Rep
March 2025
School of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China.
Distributed Bragg reflector (DBR) absorptive materials have broad applications in optical fibre communications, solar cells, and other fields. This study adopts dispersion polymerization to prepare monodisperse polystyrene (PS) microspheres. Graphene quantum dots (GQDs) are prepared using the ultrasonic dispersion method.
View Article and Find Full Text PDFNano Lett
March 2025
Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506, United States.
Crystal defects, whether intrinsic or engineered, drive many fundamental phenomena and novel functionalities of quantum materials. Here, we report symmetry-breaking phenomena induced by Sn vacancy defects on the surface of epitaxial Kagome antiferromagnetic FeSn films using low-temperature scanning tunneling microscopy and spectroscopy. Near the single Sn vacancy, anisotropic quasiparticle interference patterns are observed in the differential conductance d/d maps, breaking the 6-fold rotational symmetry of the Kagome layer.
View Article and Find Full Text PDFPestic Biochem Physiol
April 2025
Shanxi Key Laboratory of Nucleic Acid Biopesticides, School of Synthetic Biology, Shanxi University, Taiyuan, Shanxi 030006, China; School of Life Science, Shanxi University, Taiyuan, Shanxi 030006, China; Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi 030006, China. Electronic address:
The instability of double-stranded RNA (dsRNA) restricts the application of RNA interference (RNAi) technology in agricultural pest management. Various types of nanocarriers have been developed and employed for the stable delivery of dsRNA. Nonetheless, it remains unclear which type of nanomaterial could deliver dsRNA stably and efficiently for gene knockdown in Locusta migratoria.
View Article and Find Full Text PDFAdv Mater
March 2025
Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 117585, Republic of Singapore.
Tuning transition metal spin states potentially offers a powerful means to control electrocatalyst activity. However, implementing such a strategy in electrochemical CO reduction (COR) is challenging since rational design rules have yet to be elucidated. Here we show how the addition of P dopants to a ferromagnetic element (Fe, Co, and Ni) single-atom catalyst (SAC) can shift its spin state.
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