Nearly linear orbital molecules on a pyrochlore lattice.

The interplay of spin-orbit coupling with other relevant parameters gives rise to the rich phase competition in complex ruthenates featuring octahedrally coordinated Ru. While locally, spin-orbit coupling stabilizes a nonmagnetic = 0 state, intersite interactions resolve one of two distinct phases at low temperatures: an excitonic magnet stabilized by the magnetic exchange of upper-lying = 1 states or Ru molecular orbital dimers driven by direct orbital overlap. Pyrochlore ruthenates RuO ( = rare earth, Y) are candidate excitonic magnets with geometrical frustration.

Evidence of superconducting Fermi arcs.

An essential ingredient for the production of Majorana fermions for use in quantum computing is topological superconductivity. As bulk topological superconductors remain elusive, the most promising approaches exploit proximity-induced superconductivity, making systems fragile and difficult to realize. Due to their intrinsic topology, Weyl semimetals are also potential candidates, but have always been connected with bulk superconductivity, leaving the possibility of intrinsic superconductivity of their topological surface states, the Fermi arcs, practically without attention, even from the theory side.

Fermi surface tomography.

Fermi surfaces are essential for predicting, characterizing and controlling the properties of crystalline metals and semiconductors. Angle-resolved photoemission spectroscopy (ARPES) is the only technique directly probing the Fermi surface by measuring the Fermi momenta (k) from energy- and angular distribution of photoelectrons dislodged by monochromatic light. Existing apparatus is able to determine a number of k -vectors simultaneously, but direct high-resolution 3D Fermi surface mapping remains problematic.

[BIOMECHANICAL EVALUATION OF PRIMARY REPLACEMENT ARTHOPLASTY FOR UNSTABLE INTERTROCHANTERIC FRACTURES].

Aim - to study peculiarities of changes of stress-strain state in the proximal femur around the implanted femoral component of hip prosthesis in case of inter-trochanteric fracture on the background of involutive osteoporosis in connection with functional loading by numeral analysis on a mathematical model. Using program SolidWorks 2 variants of finite element models of inter-trochanteric fractures were built, including type 31-A2, with the implantation of the femoral component of hip prosthesis - without restoration and with the restoration of the intertrochanteric region and calcar with a ring-shaped graft. The simulated load is single-support standing and the action of the musculo-ligamentous apparatus in the vertical position of the body.

Superconductivity in (Ba,K)SbO.

(Ba,K)BiO constitute an interesting class of superconductors, where the remarkably high superconducting transition temperature T of 30 K arises in proximity to charge density wave order. However, the precise mechanism behind these phases remains unclear. Here, enabled by high-pressure synthesis, we report superconductivity in (Ba,K)SbO with a positive oxygen-metal charge transfer energy in contrast to (Ba,K)BiO.