Stanene has been predicted to be a two-dimensional topological insulator, providing an ideal platform for the realization of quantum spin Hall effect even at room temperature. Based on first-principles calculations, we studied the topological edge states in zigzag chlorinated stanene nanoribbon. From our calculations, dual Dirac points can be found near Fermi level. One Dirac point is localized at the edges and emerges in a narrow nanoribbon, while another is widespread and can only be found in a wide nanoribbon due to the coupling of two opposite edges. At the localized Dirac point, there is an interesting odd-even oscillated energy gap with the change of the width of nanoribbon. The energy gaps at both Dirac points and the coupling of two opposite edges can be modified by edge adsorption. Asymmetric adsorption of two edges was also discussed. Our calculations may be helpful for the potential applications of tin-based topological nanoribbons in nanodevices.
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http://dx.doi.org/10.1088/1361-648X/ac0752 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan.
Graphene-based supercapacitors have gained significant attention due to their exceptional energy storage capabilities. Despite numerous research efforts trying to improve the performance, the challenge of experimentally elucidating the nanoscale-interface molecular characteristics still needs to be tackled for device optimizations in commercial applications. To address this, we have conducted a series of experiments using substrate-free graphene field-effect transistors (SF-GFETs) and oxide-supported graphene field-effect transistors (OS-GFETs) to elucidate the graphene-electrolyte interfacial arrangement and corresponding capacitance under different surface potential states and ionic concentration environments.
View Article and Find Full Text PDFSci Rep
January 2025
Saint Petersburg State University, St. Petersburg, 198504, Russia.
Using angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT), an experimental and theoretical study of changes in the electronic structure (dispersion dependencies) and corresponding modification of the energy band gap at the Dirac point (DP) for topological insulator (TI) [Formula: see text] have been carried out with gradual replacement of magnetic Mn atoms by non-magnetic Ge atoms when concentration of the latter was varied from 10% to 75%. It was shown that when Ge concentration increases, the bulk band gap decreases and reaches zero plateau in the concentration range of 45-60% while trivial surface states (TrSS) are present and exhibit an energy splitting of 100 and 70 meV in different types of measurements. It was also shown that TSS disappear from the measured band dispersions at a Ge concentration of about 40%.
View Article and Find Full Text PDFAdv Mater
January 2025
CAS Center for Excellence in Nanoscience, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, China.
Nat Commun
January 2025
Department of Physics and HK Institute of Quantum Science & Technology, The University of Hong Kong, Hong Kong, Hong Kong.
Quantum entanglement uncovers the essential principles of quantum matter, yet determining its structure in realistic many-body systems poses significant challenges. Here, we employ a protocol, dubbed entanglement microscopy, to reveal the multipartite entanglement encoded in the full reduced density matrix of the microscopic subregion in spin and fermionic many-body systems. We exemplify our method by studying the phase diagram near quantum critical points (QCP) in 2 spatial dimensions: the transverse field Ising model and a Gross-Neveu-Yukawa transition of Dirac fermions.
View Article and Find Full Text PDFNature
January 2025
Edward L. Ginzton Laboratory, Stanford University, Stanford, CA, USA.
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