Publications by authors named "Karol Flachbart"

A detailed study of charge transport in the paramagnetic phase of the cage-cluster dodecaboride Ho0.8Lu0.2B12 with an instability both of the fcc lattice (cooperative Jahn−Teller effect) and the electronic structure (dynamic charge stripes) was carried out at temperatures 1.

View Article and Find Full Text PDF

We present a study of the ground state and stability of the fractional plateau phase (FPP) with M/M = 1/8 in the metallic Shastry-Sutherland system TmB. Magnetization (M) measurements show that the FPP states are thermodynamically stable when the sample is cooled in constant magnetic field from the paramagnetic phase to the ordered one at 2 K. On the other hand, after zero-field cooling and subsequent magnetization these states appear to be of dynamic origin.

View Article and Find Full Text PDF

SmB has recently attracted considerable interest as a candidate for the first strongly correlated topological insulator. Such materials promise entirely new properties such as correlation-enhanced bulk bandgaps or a Fermi surface from spin excitations. Whether SmB and its surface states are topological or trivial is still heavily disputed however, and a solution is hindered by major disagreement between angle-resolved photoemission (ARPES) and scanning tunneling microscopy (STM) results.

View Article and Find Full Text PDF

We have investigated the rotating magnetocaloric effect (R-MCE) of TmB - an anisotropic magnetic system with geometrical frustration of Shastry-Sutherland type. The R-MCE was obtained from detailed temperature dependencies of heat capacity in various magnetic fields of a single crystalline sample for crystal axes orientations c || B and c ⊥ B. The received results exhibit rather complex distributions of positive and negative entropy ΔS(T, B) and temperature ΔT(T, B) differences below and above T when the direction of the magnetic field changes between directions c || B and c ⊥ B.

View Article and Find Full Text PDF