• Denys Kononenko
    • The general approach for description of antiferromagnetic textures in curvilinear one-dimensional systems is developed.
  • Kostiantyn Yershov
    • Proposed a minimal extension of the anisotropic Heisenberg model in order to describe the flexible magnetic wires -- Phys. Rev. B 99, 014404 (2019).
    • Spontaneous deformations of elastic magnetic films induced by chiral magnetic interactions -- Phys. Rev. B 100, 140407(R) (2019).
    • Curvature induced modification of critical value of Dzyaloshinskii-Moriya interaction constant in chiral magnets  -- https://arxiv.org/abs/2001.07618.
    • Presented a general approach for studying the dynamics of domain walls in biaxial ferromagnetic stripes with functionally graded Dzyaloshinskii--Moriya interaction. By engineering the spatial profile of the Dzyaloshinskii--Moriya interaction parameter we propose the concept of a diode, which implements filtering of domain walls of certain topological charge and helicity --  https://arxiv.org/abs/2004.02175.
  • Volodymyr Bezguba
    • It is demonstrated that FeTe1−xSex (x=0.45) is a superconducting 3D Dirac semimetal hosting type-I and type-II Dirac points and that its electronic structure remains topologically trivial -- https://arxiv.org/abs/1909.10806.
  • Mykola Kovbasa
    • We have studied the plasmon dispersion as well as the momentum dependence of plasmon width/damping inthe quasi one-dimensional metal TTF-TCNQ. An energy upshift upon going to lower temperatures is observed, aquantitative, microscopic explanation however is not available yet. Upon incraesing momentum, the plasmonspectral width initially remains constant before it increases visibly above a momentum transfer of about 0.3Å−1Å.This suggests an additional damping mechanism which sets in at this momentum, which most likely is due to inter-band transitions - Mater. Res. Express 6, 106319 (2019).
  • Pavlo Khanenko
    • Determined the coherence length in iron based superconductor LiFeAs by numerical method using STM data.
  • Yulia Shemerlyuk
    • MPS3 family (FePS3, NiPS3, NixFe1-xPS3, MnPS3, VxPS3 ) were synthesized as single crystals using CVT methods. The analysis of magnetic properties of single crystals of layered MnPS3, FePS3, and NiPS3  showed that all the materials are ordered antiferromagnetically at low temperatures. In the paramagnetic mode, the anisotropies are different: susceptibility of MnPS3 is isotropic, and NiPS3 has only weak anisotropy, FePS3 exhibits large anisotropic susceptibility behavior.
  • Iryna Kovalchuk
    • Series of Pt1xRhxBi2 samples was obtained and studied. It has been found that at low temperature trigonal-structure Pt1xRhxBi2 compounds undergo superconducting transition with the critical temperature that increases from Tc=600 mK for x=0 up to Tc=2.7 K for x=0.35. It is shown that, due to the topological properties of the electronic band structure, this material is a candidate for topological superconductivity -- https://arxiv.org/abs/2002.03976.
  • Vitaliy Romaka
    • Single crystal of topological Co2MnGa Heusler-type ferromagnet has been grown using the optical floating zone (OFZ) technique. The compound shows structural phase transition from L21 to B2-type structure, which, however has practically no effect on it's ferromagnetic properties. In order to shed a light on effects of structural disorder a zero-field NMR measurements were carried accompanied by thermodynamic DFT modeling.
    • A series of non-centrosymmetric compounds of the Fe2P family - RAuIn intermetallics (R – rare-earth metals), which are characterized by the non-centrosymmetric P-62m space group and crystallize in the ZrNiAl. structure type were studied due to the potential for complex magnetic phase diagrams and the possibility of studying the interplay with conduction electrons. Analysis of the known RAuIn compounds allowed us to predict and experimentally confirm the existence of the new and final representative of this series – ScAuIn. For this compound, magnetic properties and specific heat were studied and DFT modeling was performed. Single crystalline samples of two other isostructural NdAuIn and SmAuIn compounds have been grown and their structural, thermal, and magnetic properties were characterized. Magnetization measurements performed with a vibrating sample magnetometer (VSM) evidence an antiferromagnetic-like transition in single crystals of SmAuIn with TN ~ 7.5 K. On the other hand, single crystals of NdAuIn do not present any magnetic transition down to 1.8 K.
  • Lesia Voloshyna
    • The growth of the good-shaped LSCO-Nd (La1.61Nd0.2Sr0.19CuO4) single crystals by the travelling solvent floating zone.

WSTopoUKRATOP students and invited researchers from KAU and NAS of Ukraine took part in the Workshop on Topological Phenomena in Quantum Materials at IFW Dresden on 4-5 December 2018. 

 

4b 7569cThe 2nd UKRATOP Workshop took place at IFW Dresden on December 3, 2018. The aim of the meeting was to discuss the organizational questions and listen to short (10+5 minutes) presentations of the students and postdocs. During the 5 minutes after-talk discussions the supervisors gave an overview of the scientific plans. 

Lab tours and bilateral discussions have been organized after lunch. Ukrainian delegation has also enjoyed Dresdner Weihnachtsmarkts.

1stSelectThe 1st UKRATOP Selection Workshop took place at KAU on May 29-30, 2018.

We congratulate 5 master students, 1 PhD student and 2 postdocs who have been selected to join the research groups at IFW Dresden starting from October 1.