B. Verkin Institute for Low Temperature Physics and Engineering

Department of Theoretical Physics

Laboratory of Numerical Methods in Theoretical Physics


Head of the Laboratory

Victor Slavin

+38 (057) 751-55-35

slavin@ilt.kharkov.ua

Laboratory Staff

Main scientific fields:

  • Low-dimensional frustrated magnetic systems.
  • Transport and thermodynamic properties of low-dimensional strongly-correlated disordered conductors.
  • Quantum computing and quantum information theory.
  • Theoretical study on the microscopic level of quasiparticle spectra and their physical characteristics of crystals with complex defective structure, disordered compounds, quasi-low-dimensional systems, as well as micro and nano objects.
  • Investigation of the propagation of acoustic waves in heterostructures and their manifestation in observed thermodynamic and kinetic properties (in particular Kapitza resistance and Fano-resonance).

Here are some illustrations of our investigations.

All images are clickable.


The ground state structure of M=1/3 phase in Shastry-Sutherland Lattice.

3D

Anisotropic young's modulus of diamond crystal.

3D

Electron spectra of graphene with zig-zag boundary.

Electron spectra of graphene with zig-zag boundary

It is shown here, that in electron spectra of graphene with zig-zag boundary, there appear the waves, split of the bands of quasi-continuous spectrum, which propagate along the boundary and decay with a distance from it. They, moreover, propagate only via the atoms of sub-lattice, which contains atoms with dangling bond, appeared with a formation of boundary. Dispersion of these waves is determined by character of relaxation processes during formation of the boundary. Dispersion in electron spectrum is relativistic, but corresponds to the significantly less values of group velocity, compared to infinite monolayer of graphene. The similar behavior is demonstrated by electron spectra of graphene with isolated vacancy. The split gap waves lead to a formation on local densities of state of the sharp resonances, which enrich significantly electron spectrum near Fermi level, as well as phonon spectrum near the point of intersection of acoustic and optical branches, polarized normally to the plane of graphene monolayer. These phonons within a considered frequency range do not practically interact with differently polarized phonons, and also possess high group velocities, which there dominant contribution to electron-phonon coupling. The presented results demonstrate a possibility to facilitate superconductivity in a graphene matter by a controlled creation of defects like vacancy or zig-zag boundary, which distort the atomic bonding in a particular sub-lattice of graphene monolayer.