ELFT HÍRADÓ

[Janos Asboth <asboth.janos AT wigner.mta.hu>]

*WIGNER SZFI Seminar*
Topological Magnons in Kitaev Magnets at High Fields

*Karlo Penc*
Wigner Research Centre for Physics, Inst. of Solid State Physics and
Optics, Budapest

Tuesday, 30 October 2018 10:00, KFKI Campus, Bldg. 1, 2nd floor, Conference
Room
We study the Kitaev-Heisenberg-Gamma-Gamma' model that describes the
magnetism in strong spin-orbit coupled honeycomb lattice Mott insulators.
In strong [111] magnetic fields that bring the system into the fully
polarized paramagnetic phase, we find that the spin wave bands carry
nontrivial Chern numbers over large regions of the phase diagram implying
the presence of chiral magnon edge states. In contrast to other topological
magnon systems, the topological nontriviality of these systems results from
the presence of magnon number non-conserving terms in the Hamiltonian.
Since the effects of interactions are suppressed by J/h, the validity of
the single particle picture is tunable making paramagnetic phases
particularly suitable for the exploration of this physics. Using time
dependent DMRG and interacting spin wave theory, we demonstrate the
presence of the chiral edge mode and its evolution with field.



Everyone is welcome to attend.

János Asbóth
szfi-seminar AT wigner.mta.hu