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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

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

This year’s recipient of the highest award in the field of physics, the Blinc Lifetime Award, is our colleague, prof. Igor Muševič. Igor is the head of the liquid crystal physics laboratory, and he also very successfully led our department for 16 years. He won the award for outstanding research achievements in the field of liquid crystal physics, creating new areas of research and mentoring top researchers. Igor is the author of many breakthrough discoveries published in the most prestigious journals, the author of two high-profile monographs, the PI of many projects, including the ongoing ERC project LOGOS, and an excellent and respected lecturer at international conferences and at the University of Ljubljana. Congratulations!

Our coworker Anna Razumnaya, in collaboration with the Helmholtz-Zentrum Berlin für Materialien und Energie (Germany), the University of Picardie Jules Verne (France), and the CEMES-CNRS and Université de Toulouse (France), reported Switchable Topological Polar States in Epitaxial

BaTiO3 Nanoislands on Silicon in Nature Communications.

This study presents the creation of epitaxial BaTiO3 nanoislands on silicon, featuring chiral topological polar textures. These structures demonstrate unique center-type polarization domains that can be reversibly switched under an electric field. Insights into their 3D polarization patterns were achieved through piezoresponse force microscopy and phase-field modeling. The findings highlight a promising approach for integrating functional ferroelectric nanostructures into silicon-based platforms for next-generation nanoelectronic devices.

DOI: https://www.nature.com/articles/s41467-024-54285-z