In the search of topological superconductors, nailing down the Fermiology of the normal state is as crucial a prerequisite as unraveling the superconducting pairing symmetry. In particular, the number of time-reversal-invariant momenta (TRIM) in the Brillouin zone enclosed by Fermi surfaces is closely linked to the topological class of time-reversal-invariant systems, and can experimentally be investigated. We report here a detailed study of de Haas van Alphen quantum oscillations in single crystals of the topological semimetal CaSnwith torque magnetometry in high magnetic fields up to 35 T. In conjunction with density functional theory based calculations, the observed quantum oscillations frequencies indicate that the Fermi surfaces of CaSnenclose an odd number of TRIM, satisfying one of the proposed criteria to realize topological superconductivity. Nonzero Berry phases extracted from the magnetic oscillations also support the nontrivial topological nature of CaSn.
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http://dx.doi.org/10.1088/1361-648X/abe0e2 | DOI Listing |
Nano Lett
January 2025
State Key Laboratory of Structural Analysis for Industrial Equipment & School of Physics, Dalian University of Technology, Dalian 116024 People's Republic of China.
Talanta
January 2025
MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou, China. Electronic address:
The current surface-enhanced Raman scattering (SERS) substrates typically feature a single energy level, posing challenges in coordinating electromagnetic enhancement (EM) and chemical enhancement (CM), thereby limiting the sensitive detection of numerous crucial target molecules. In this study, novel aggregated nanorings (a-NRs) hybridizing Ag, Au and AgCl are constructed as SERS substrates. On one hand, the obtained a-NRs exhibit robust localized surface plasmon resonance absorption, whose wavelength can be tuned to match three commonly used laser wavelengths (532, 633 and 785 nm) to gain strong EM effect.
View Article and Find Full Text PDFSci Rep
January 2025
School of Information Technology, Jiangsu Open University, Nanjing, 210017, China.
Because of its dimensional characteristics, two-dimensional (2D) materials exhibit many special properties. The key to researching their features is to prepare high-quality larger-area monolayer 2D materials. Metal-assisted mechanical exfoliation method offers the possibility.
View Article and Find Full Text PDFNat Commun
January 2025
Tsung-Dao Lee Institute & School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, China.
Unconventional superconductivity is known for its intertwining with other correlated states, making exploration of the intertwined orders important for understanding its pairing mechanism. In particular, spin and nematic orders are widely observed in iron-based superconductors; however, the presence of charge order is uncommon. Using scanning tunnelling microscopy, and through expanding the phase diagram of iron-arsenide superconductor BaKFeAs to the hole-doping regime beyond KFeAs by surface doping, we demonstrate the formation of a charge density wave (CDW) on the arsenide surface of heavily hole-doped BaKFeAs.
View Article and Find Full Text PDFJ Phys Condens Matter
January 2025
Shandong University, Binhai Road 72, Jimo, Qingdao, Shandong, 266237, CHINA.
Magnetic Weyl semimetals (WSM) have recently attracted much attention due to their potential in realizing strong anomalous Hall effects. Yet, how to design such systems remains unclear. Based on first-principles calculations, we show here that the ferromagnetic half-metallic compound InCoSehas several pairs of Weyl points and is hence a good candidate for magnetic WSM.
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