ELFT HÍRADÓ

[tcsaba <tcsaba AT eik.bme.hu>]

                 M E G H Í V Ó - I N V I T A T I O N

    Seminar Series of the Department of Theoretical Physics at the
           Budapest University of Technology and Economics


                           Karlo Penc
              (Wigner Research Institute for Physics,
                  Hungarian Academy of Science)


        Topological Magnons in Kitaev Magnets at High Fields


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.


Időpont: 2018. szeptember 21. péntek, 10:15
Helyszín: BME Fizikai Intézet, Elméleti Fizika Tanszék,
Budafoki út 8. F-épület, III lépcsőház, szemináriumi szoba