We have performed a comprehensive study of quantum magnetism in the TeVO4 system. An impressive correspondence between a broad variety of experimental results (neutron diffraction and magnetization measurements in pulsed high-magnetic fields) with the theory emphasizes the TeVO4 compound to be a model system of a frustrated spin chain with a rich phase diagram. The main result is a discovery of a magnetic stripe structure on the nano-scale, which appears at the transition between the spiral and collinear magnetic orders.
COBISS.SI-ID: 28648487
We have studied structurally simple quantum antiferromagnet CsO2 where the interplay of spin degrees of freedom with lattice vibrations and orbital ordering leads to complex and interesting physics. Using magnetic resonance techniques, we have shown that the system exhibits an exotic Tomonaga-Luttinger-liquid state at low temperatures, where orbital ordering takes place. Sizeable lattice vibrations at higher temperatures lead to the huge temperature dependence of the exchange interaction, providing the first clear demonstration of this effect predicted three decades ago.
COBISS.SI-ID: 28759079
We have discovered a new type of metallic state by studying a superconductor made from C60 molecules. The new state has emerged during systematic change of the distance between neighbouring C60 molecules by doping the parent Cs3C60 compound with rubidium. The study reveals that the material has a remarkably rich combination of insulating, magnetic, metallic and superconducting phases – including the hitherto unknown state, which the researchers have dub a "Jahn–Teller metal". These studies are extremely important for our understanding how superconductivity evolves in cases when several degrees of freedom are intertwined – in our case these are electronic, spin and molecular degrees of freedom.
COBISS.SI-ID: 28519207
We have studied mixed ferro/antiferromagnetic phase in the Cu3Bi(SeO3)2O2Br system. The results reveal the ability of metamagnetic materials to absorb electromagnetic radiation in an extremely broad frequency range. The effect is controlled by the external magnetic field, which actuates a mixed ferro/antiferromagnetic phase, where the absorption in Cu3Bi(SeO3)2O2Br system extends over at least nine orders of frequency scale. Considering that artificial metamagnets (magnetic multilayers) allow for a direct control over the required magnetic field, a novel way of tuning the material’s functional properties is imminent.
COBISS.SI-ID: 28566311
We have reported physical properties of the first hexagonal high-entropy alloy Ho-Dy-Y-Gd-Tb. We have determined magnetic phase diagram, which in zero magnetic field shows a transition to a helical antiferromagnetic state at high temperatures, whereas at low temperatures a new kind of a spin-glass phase appears. In a magnetic field, discontinuous metamagnetic phase transitions to exotic spin phases occur.
COBISS.SI-ID: 29086503