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Using scanning tunneling microscopy and spectroscopy we demonstrate a revival of magnetism in 7-armchair nanoribbon by unpassivated atoms at the termini. Namely, a pair of intense Kondo resonances emerges at the peripheries of zigzag terminus revealing the many-body screening effects of local magnetic moments. Although Kondo resonance originates from a missing local orbital, it extends to a distance of 2.5 nm along the edge of the ribbon. The results are complemented by density functional theory calculations which suggest a possible coupling between Kondo states despite screening effects of substrate electrons. These findings indicate a possibility to restore intrinsic magnetic ordering in graphene nanoribbon without major structural modifications

DOI: https://doi.org/10.1038/s41598-024-62624-9

Smectic A (SmA) liquid crystals can be viewed as model systems for lamellar structures. They bridge the study of broken orientational symmetry, the statistical mechanics of membranes, and the long-range periodic order in crystals. Among others, they provide an arena to systematically study the effects of nonlinear elasticity. We demonstrated that a nonlinear energy description is required which is not captured in the classical Landau-de Gennes-Ginsburg model in order to explain the observed layer spacing of highly curved SmA layers. Using X-ray diffraction, we quantitatively determined the dilation of bent layers distorted by antagonistic anchoring. We showed that combined X-ray measurements and theoretical modeling allow for the quantitative determination of the number of curved smectic layers and their thickness in dilated regions.

DOI: https://doi.org/10.1103/PhysRevLett.134.018101

The 21st century has witnessed a paradigm shift in material science, driven by the application of topological principles offering a global perspective on material properties beyond traditional local interactions. Ferroelectrics, known for their spontaneous polarization and technological significance, have now emerged as a rich platform for hosting fundamental topological states at the nanoscale. This Review explores the topological foundation of ferroelectricity, rooted in the electrostatic essence of these materials. Drawing upon the analogy between the hydrodynamics of incompressible fluids and the electrostatics of polarization fields, we establish a comprehensive framework for classifying the complex topological states observed in ferroelectrics. We demonstrate that the rich diversity of polarization structures can be exhaustively described using the advanced topological approach. By extending fundamental topological concepts such as helicity, fibration, foliation, and ergodicity, we offer a systematic analysis of the topological textures in ferroelectrics. This work provides a coherent framework for understanding and manipulating topological structures in nanostructured ferroelectrics, paving the way for innovations in materials science and technology.

DOI: https://doi.org/10.1016/j.physrep.2025.01.002

To visualize the intrinsic band structure of armchair graphene nanoribbon and verify theories, the terminus is covalently bonded to Au-coated tip. Tunneling spectroscopies with these suspended nanoribbons exhibit symmetric onsets of conduction and valence bands around zero bias. From these results, a value of 2.78 eV for the band gap is determined which agrees very well with theoretical calculations.

Interestingly, the formation of C—Au bond suppresses Schottky contact resistance which is one of the essential prerequisites for future nanoribbon electronics.

DOI: https://onlinelibrary.wiley.com/doi/10.1002/pssr.202470030

We developed flexible and eco-friendly composite films, prepared by vacuum filtration or solvent casting method from the native or carboxylated cellulose nanofibrils and high electrically and thermally conductive 2D titanium carbide (Ti3C2Tx) MXenes. The electrostatic repulsion and hydrogen bonding between the hydrophilic surface/terminal groups on cellulose and MXene was shown to render their self-assembly distribution and organization into morphologically differently structured films with, consequently, different functional properties. A strong enhancement (for an order of magnitude) of the dielectric permittivity on increasing MXene content demonstrates the potential of developed material for applications in flexible dielectric and piezoelectric devices.

DOI: https://doi.org/10.1063/5.0232250