The cloaking effect of electronic states was only reported in bilayer graphene. Here in this work we show that this effect can also be induced in armchair graphene nanoribbons (AGNRs), by potential barriers that modulate the chirality property of the system (correlation between pseudospins). These barriers manipulate the chirality and generates pseudospin polarizations on the sides of the barrier, which leaves spatial regions in evidence, in which states behave differently. In AGNRs the extended states (ES), associated with the tunneling of Klein, use only some sites in the nanoribbon lattice (sublattice of ES). On the other hand, the barrier applied in the nanoribbon, induces states totally localized within the region of the barrier, these states use only the sites not used by the sublattice of ES. The localized states remain invisible for electronic transport for all the energies and characteristics of the barrier in the region of the first effective transport band, the same as the states are changing. This electronic cloaking effect can be suppressed by the application of a magnetic field, detecting in the conductance the previously invisible states in the form of Fano resonances. We discuss here the possibility of using this cloaking effect to generate mechanisms that can hide information or to activate hidden system effects.
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http://dx.doi.org/10.1088/1361-648X/ac09a7 | DOI Listing |
Soft Matter
January 2025
Department of Physics, Government College of Engineering and Textile Technology, 12 William Carey Road, Serampore, Hooghly-712201, India.
The theoretical study of instabilities, thermal fluctuations, and topological defects in the crystal-rotator-I-rotator-II (X-R-R) phase transitions of -alkanes has been conducted. First, we examine the nature of the R-R phase transition in nanoconfined alkanes. We propose that under confined conditions, the presence of quenched random orientational disorder makes the R phase unstable.
View Article and Find Full Text PDFMater Horiz
January 2025
School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
The quantum anomalous Hall effect (QAHE) with a high Chern number hosts multiple dissipationless chiral edge channels, which is of fundamental interest and promising for applications in spintronics. However, QAHE is currently limited in two-dimensional (2D) ferromagnets with Chern number . Using a tight-binding model, we put forward that Floquet engineering offers a strategy to achieve QAHE in 2D nonmagnets, and, in contrast to generally reported QAHE in 2D ferromagnets, a high-Chern-number is obtained accompanied by the emergence of two chiral edge states.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China.
Effective delivery and controlled release of metallo-prodrugs with sustained activation and rapid response feed the needs of precise medicine in metal chemotherapeutics. However, gold-based anticancer drugs often suffer from detoxification binding and extracellular transfer by sulfur-containing peptides. To address this challenge, we integrate a thiol-activated prodrug strategy of newly prepared hypercoordinated carbon-centered gold(I) clusters (HCGCs) with their photosensitization character to augment the mitochondrial release of Au(I) in tumors.
View Article and Find Full Text PDFOrg Lett
January 2025
Key Laboratory of Chemical Biology and Traditional Chinese Medicine (Ministry of Educational of China), Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, China.
We disclose herein a chiral phosphoric-acid-catalyzed enantioselective addition reaction of alcohols to fluoroalkylated biaryl 1,3-oxoazepines, which furnished a wide range of bridged biaryls bearing a fluoroalkylated quaternary carbon stereocenter on the seven-membered ring in high yields (up to 99%) with excellent enantioselectivities (up to 98% ee). Our method can be used for the modification of several natural products and bioactive molecules. Preliminary studies revealed that the products obtained in this reaction exhibit good in vitro bioactivities against two plant pathogens.
View Article and Find Full Text PDFJ Biol Rhythms
January 2025
Department of Physics and i3n, University of Aveiro, Aveiro, Portugal.
The role of the hierarchical organization of the suprachiasmatic nucleus (SCN) in its functioning, jet lag, and the light treatment of jet lag remains poorly understood. Using the core-shell model, we mimic collective behavior of the core and shell populations of the SCN oscillators in transient states after rapid traveling east and west. The existence of a special region of slow dynamical states of the SCN oscillators can explain phenomena such as the east-west asymmetry of jet lag, instances when entrainment to an advance is via delay shifts, and the dynamics of jet lag recovery time.
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