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Na Univerzi v Ljubljani so 9. oktobra 2026 že petič podelili nagrade in pohvale dr. Uroša Seljaka za najboljše znanstvene članke študentk in študentov prve in druge stopnje študija v Sloveniji.

Med letošnjimi nagrajenci je tudi Sara Klopčič z Instituta »Jožef Stefan«, ki je nagrado prejela za znanstveni članek Electrically and Geometrically Tunable Photon Pair Entanglement from Ferroelectric Nematic Liquid Crystal (Električno in geometrijsko nastavljiva prepletenost parov fotonov iz feroelektričnega nematskega tekočega kristala).

Njen mentor, izr. prof. dr. Matjaž Humar z Odseka za fiziko trdne snovi Instituta »Jožef Stefan« in Fakultete za matematiko in fiziko Univerze v Ljubljani, je skupaj z nagrajenko prejel plaketo za mentorsko delo.

Nagrada dr. Uroša Seljaka spodbuja študentke in študente k znanstvenemu raziskovanju že med študijem ter poudarja pomen dobrega mentorstva pri doseganju izjemnih raziskovalnih rezultatov.

Marta Lavrič, in collaboration with a group from Department of Complex Matter F7 (A. Sterle, P. Medle Rupnik, L. Cmok, A. Erkoreka, N. Osterman, A. Mertelj, N. Sebastián) and research groups from University of Leeds (C. J. Gibb, J. Hobbs, R. J. Mandle) and University of the Basque Country (A. Erkoreka, J. Martinez-Perdiguero), has published an article entitled “Elasticity-Driven Periodic Polarization Patterns in a Chiral Ferroelectric Nematic Fluid” in Advanced Materials.

The interplay between chirality, confinement and elasticity can drive the spontaneous formation of complex polarization patterns in chiral ferroelectric nematic liquid crystals. These three factors work together to transform an initially uniform state into a variety of ordered structures.

In a new study the researchers show that when the pitch of the material under confinement deviates from its natural pitch, periodic instabilities emerge as the material approaches a heliconical polar state. Near such transition, the bend elastic constant of the liquid crystal softens. The combination of the material’s preferred helical structure, confinement and reduced resistance to bending drives the formation of periodic polarization patterns.

Under confinement, these instabilities give rise to a variety of self-organized structures, including stripes, squares and hexagonal patterns. By changing the thickness of the confined material and the surface alignment, the researchers can control which structures emerge.… Read the rest “Article in Advanced Materials: Elasticity-Driven Periodic Polarization Patterns in a Chiral Ferroelectric Nematic Fluid”

Marta Lavrič and George Cordoyiannis, in collaboration with coworkers from Complex Matter Department (A. Sterle, N. Sebastian, and A. Mertlej) and research groups from Czech Academy of Sciences (N. Podoliak, M. Cigl, P. Golub, V. Novotna) and University of the Basque Country (A. Erkoreka, J. Martinez-Perdiguero), have published an article entitled “The effect of side chain length on the mesomorphic properties of ferroelectric nematogens” in Materials Advances.

In this paper, a previously reported ferroelectric nematogen bearing a dimethylamino-terminated part was modified and explored. The effect of terminal group and molecular length on the mesomorphic properties was investigated in two new homologues. While previously reported shorter homologues exhibited a direct phase transition from the isotropic to the ferroelectric nematic phase, for prolonged alkyl chain a narrow nematic phase exists in-between. The mesomorphic and material properties of new compounds were established, and ferroelectricity was confirmed combining polarization, SHG signal and permittivity measurements.

DOI: 10.1039/d6ma00897f

Marta Lavrič, in collaboration with a group from Prague (M. Cigl, N. Podoliak, D. Repček, P. Golub and V. Novotna), has published an article entitled “The effect of fluorine or chlorine substitution on mesomorphic properties of ferroelectric nematic liquid crystals” in Materials Advances.

Ferroelectric nematic phase (NF) represents an attractive and rapidly developing area of liquid crystals, combining fluidity with ferroelectricity. NF materials exhibit large polarization values and remarkable non-linear optical properties. In this article an original molecular structure, non-substituted and with halogen substituents in the position of an electron donating group was designed, taking into consideration that application of Cl atom has been utilized for the first time in the design of ferroelectric nematogens. For homologues with a prolonged molecular core, we observed the ferroelectric nematic phase (NF) below the nematic one during the cooling process. Moreover, for non-substituted homologue, the NF phase is enantiotropic in a broad temperature range. The presented results provide valuable insight into the design of ferroelectric nematic liquid crystalline compounds.

DOI: 10.1039/D6MA00129G

Raziskovalci z Odseka za fiziko trdne snovi Instituta Jožef Stefan in Fakultete za matematiko in fiziko Univerze v Ljubljani so skupaj s sodelavci iz Japonske, ZDA in Grčije odkrili robustno kovinsko stanje v molekulskem materialu Yb₂CsC₆₀. Študija je bila objavljena v ugledni reviji Nature Communications.

Obsežna raziskava obravnava obnašanje močnih elektronskih korelacij v molekulskih kristalih na osnovi fulerenov, ki vsebujejo eno »vrzel« v večorbitalnih elektronskih stanjih. Z uporabo sinhrotronske rentgenske difrakcije, sipanja nevtronov, Ramanske spektroskopije, jedrske magnetne resonance, rentgenske absorpcijske spektroskopije ter DFT izračunov je raziskovalna skupina pokazala, da Yb₂CsC₆₀ ostane kovinski in ne preide v Mottovo izolatorsko stanje navkljub prisotnosti elektronskih korelacij.

Rezultati razkrivajo presenetljivo analogijo med koreliranimi molekulskimi sistemi s p-elektroni in materiali na osnovi prehodnih kovin z d-elektroni, kar prinaša nov vpogled v fiziko Hundove sklopitve in močno korelirane kvantne snovi. Novo sintetizirani ortorombski fulerid bi lahko odprl tudi nove poti za odkritje nekonvencionalne superprevodnosti v sorodnih molekulskih sistemih.

Članek:
“Survival of the metallic state in a single-hole multiband p-orbital molecular system”
K. Matsui, R. A. Klein, N. Yoshikane, J. Arvanitidis, M. Gomilšek, U. Klopčič, S. Kawaguchi, H. Yamaoka, N. Hiraoka, H. Ishii, Q. Zhang, S. Mori, H. Ishibashi, Y. Kubota, Craig M. Brown, Denis Arčon, and Kosmas Prassides.… Read the rest “Članek v reviji Nature Communications o koreliranih kovinskih stanjih v fuleridih”