ELFT HÍRADÓ

[tcsaba AT eik.bme.hu]

                             MEGHÍVÓ

       a BME Fizikai Intézete Elméleti Fizika Tanszékének

                         szemináriumára:


                       Romhányi Judit
    Institut für Festkörper- und Werkstoffforschung, Dresden

           "Thermal Hall effect in SrCu2(BO3)2"


We show that SrCu2(BO3)2 (SCBO), the well-known realization of
the Shastry-Sutherland model, hosts topological triplon bands.
The Shastry-Sutherland model has an exact dimer singlet ground state.
However, the material SCBO has small Dzyaloshinskii-Moriya (DM)
interactions which admix a triplet component into the ground state.
The lowest excitations are three gapped triplon modes, well described
by bond wave theory. An applied magnetic field opens band gaps and
surprisingly, we are left with topological bands characterized by
non-zero (±2) Chern numbers. Thus, SCBO supports protected triplonic
edge modes and is a magnetic analogue of the integer quantum Hall effect.
Ultimately, this topological character stems from the DM interactions
which generate a Lorentz force for triplons. Our results may be
verified by thermal Hall measurements.



Helye: BME Fizikai Intézet, Elméleti Fizika Tanszék
Budafoki út 8. F-épület, III lépcs?ház
Szemináriumi szoba

Ideje: 2014. szeptember 26. péntek, 10:15.

Minden érdeklödöt szívesen látunk.

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