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Scanning Tunnelling Microscopy

All articles tagged with #scanning tunnelling microscopy

science-and-technology2 years ago

Unveiling the Quantum Textures of Magic-Angle Graphene's Many-Body Wavefunctions

Researchers have used high-resolution scanning tunnelling microscopy to study the wavefunctions of correlated phases in magic-angle twisted bilayer graphene (MATBG). They found distinct broken-symmetry patterns in the wavefunctions of gapped phases, including correlated insulating, pseudogap, and superconducting phases. The researchers introduced a symmetry-based analysis using complex-valued local order parameters, which revealed intricate textures that distinguish the various correlated phases. The observed quantum textures closely match those of the proposed incommensurate Kekulé spiral order in typical MATBG devices, while ultralow-strain samples exhibit local symmetries similar to a time-reversal symmetric intervalley coherent phase. The superconducting state of MATBG also shows strong signatures of intervalley coherence.

science-and-technology2 years ago

"Unprecedented Imaging: Synchrotron X-rays Capture a Single Atom"

Researchers at Argonne National Laboratory have achieved the single-atom limit in synchrotron X-ray scanning tunnelling microscopy, allowing for the characterization of materials at the atomic level. By adding a sharp metallic tip to a conventional X-ray detector, they were able to detect X-ray-excited core-level electrons in samples containing iron or terbium atoms. This breakthrough has important implications for various fields, including medical and environmental research, as it enables the investigation of individual atoms and their chemical properties. It also opens up possibilities for designing advanced materials and exploring magnetic properties for spintronic and quantum applications.