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Active nematic fluids are non-equilibrium systems characterized by a chaotic dynamic state known as active turbulence, which in three-dimensional active nematics is realized as a dynamic network of defect lines. Nika Kralj, Miha Ravnik and Žiga Kos showed how active turbulence dynamically reacts to changes in material properties and external parameters, which leads to coarsening and refinement of defect line density. In the limit of passive nematic liquids, such a phenomenon describes the last stage of the Kibble-Zurek mechanism and appears in many physical systems, from cosmic strings to superfluid helium and liquid crystals. The authors show how such a process takes place in active matter, which leads to interesting parallels with cosmic string coarsening models.

Gregor Filipič, Luka Pirker, Anja Pogačnik Krajnc, and Maja Remškar from the Department of Condensed Matter Physics F5 and Marjan Ješelnik from smartMELAMINE from Kočevje published a paper in the journal Materials with the title Enhanced Filtration Efficiency of Natural Materials with the Addition of Electrospun Poly(vinylidene fluoride-co-hexafluoropropylene) Fibres. In the article the researchers have increased the filtration efficiency of natural materials by depositing a thin layer of electrospun PVDF fibres. By optimising the layer thickness of the electrospun fibres the filtration efficiency can be tuned and thus significantly reduce the amount of plastic waste.

Luka Pirker from the Department of Condensed Matter Physics F5 together with colleagues from Jaroslav Heyrovský Institute for physical chemistry from Prague published a paper in the journal 2D Materials with the title Sulphur isotope engineering of exciton and lattice dynamics in MoS2 monolayers.

In the published paper, the researchers synthesized MoS2 with different isotopes of sulphur, revealing the influence of phonons on the optoelectronic properties of MoS2. By varying the isotopic composition, the optoelectronic properties of the material can be adjusted for various applications, and at the same time provides a unique platform for understanding the fundamentals of optical processes in 2D systems.

Luka Pirker and Maja Remškar from the Department of Condensed Matter Physics F5 and colleagues from the University of Regensburg (Germany) published a paper in the journal Advanced Materials with the title Non-Destructive Low-Temperature Contacts to MoS2 Nanoribbon and Nanotube Quantum Dots.

Molybdenum disulphide (MoS2) has inspired scientists for more than a decade with its extraordinary properties. Among others, it also has unique electrical properties, which makes it interesting for a wide range of electronic applications, from

transistors and sensors to quantum computers.

In the published article, the researchers presented a new way of making electrical contacts using bismuth on MoS2 nanotubes and nanoribbons, which were synthesized at IJS. Good electrical contacts are an important step towards quantum technologies, as most measurements take place at extremely low temperatures (T < 100 mK). The new discovery will enable researchers to discover new material properties in the quantum regime in MoS2.

George Cordoyiannis, PhD from the Department of Condensed Matter Physics F5 and colleagues from Belgium and Denmark have published inPhysica Status Solidi A the review article QCM-D Study of the Formation of Solid-Supported Artificial Lipid Membranes: State-of-the-Art, Recent Advances, and Perspectives.

An overview of the lipid vesicle adsorption and rupture under different experimental conditions is given. The current understanding of the mechanisms relies on surface sensitive techniques, such as quartz crystal microbalance with dissipation monitoring and atomic force microscopy. We provide various examples how the vesicle adsorption and rupture are influenced by varying the lipid size and charge, the type of buffer and the adhesion strength of solid substrate.