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Electron states in semiconductor materials can be modified by quantum confinement. Adding to semiconductor heterostructures the concept of lateral geometry offers the possibility to further tailor the electronic band structure with the creation of unique flat bands. Using block copolymer lithography, we describe the design, fabrication, and characterization of multiorbital bands in a honeycomb InGaAs/InP heterostructure quantum well with a lattice constant of 21 nm. Thanks to an optimized surface quality, scanning tunnelling spectroscopy reveals the existence of a strong resonance localized between the lattice sites, signature of a p-orbital flat band. Together with theoretical computations, the impact of the nanopatterning imperfections on the band structure is examined. We show that the flat band is protected against the lateral and vertical disorder, making this industry-standard system particularly attractive for the study of exotic phases of matter.
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http://dx.doi.org/10.1021/acs.nanolett.0c04268 | DOI Listing |
Phys Rev Lett
August 2025
Xiamen University, College of Physical Science and Technology, School of Electronic Science and Engineering, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, College of Energy, Fujian Key Laboratory of Ultrafast Laser Technology and Applica
The photonic flat band, defined by minimal dispersion and near-zero group velocity, has facilitated significant advances in optical technologies. The practical applications of flat bands, such as enhanced light-matter interactions, require efficient coupling to far-field radiation. However, achieving controlled coupling between flat bands and their corresponding localized modes with far-field radiation remains challenging and elusive.
View Article and Find Full Text PDFPhys Rev Lett
August 2025
Hong Kong University of Science and Technology, Department of Physics, Clear Water Bay, Hong Kong, China.
The relation between band topology and Majorana zero energy modes (MZMs) in topological superconductors had been well studied in the past decades. However, the relation between the quantum metric and MZMs has yet to be understood. In this Letter, we first construct a three band Lieb-like lattice model with an isolated flat band and tunable quantum metric.
View Article and Find Full Text PDFInorg Chem
September 2025
Department of Energy Science and Engineering, Indian Institute of Technology Bombay, Mumbai 400076, India.
A potential replacement that alleviates the shortcomings of the dominant light absorber materials used in solar photovoltaics has been synthesized, and its microstructural, electronic structure, and optical properties have been investigated. KCuS crystals were synthesized by the carbonate method. Transmission electron microscopy (TEM) established [010] as the growth direction of the needle-like monoclinic crystals.
View Article and Find Full Text PDFSmall
September 2025
Department of Materials Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan.
1D electronic structures on 2D crystalline surfaces are crucial for investigating low-dimensional quantum phenomena and enabling the development of dimensionally engineered nanodevices. However, the inherent periodic symmetry of 2D atomic lattices generally leads to delocalized electronic band extending across the surface, making the creation of periodic 1D electronic states a significant challenge. Here, robust 1D electronic ordering is demonstrated in ultrathin Mn films grown on an atomically flat, non-reconstructed body-centered cubic Fe substrate.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
August 2025
Laboratory of Physical Chemistry of Materials & Environment, Department of Physics, University of Ioannina, GR-45110 Ioannina, Greece.
The present work elucidates the role of lattice oxygen vacancies (Vs) in SrTiO (STO) nanoparticles on the spin dynamics of photogenerated charge carriers (electrons/holes, e/h) and on the photocatalytic hydrogen (H) evolution from HO. V-enriched STO materials (V-STO) were synthesized via anoxic flame spray pyrolysis (A-FSP) technology that allowed production of a library of SrTiO nanomaterials with controlled V concentrations. The optimal V-STO materials exhibited a 200% increase in photocatalytic H production rates compared with pristine STO.
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