Max Hering

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We investigate the effects of Dzyaloshinsky-Moriya (DM) interactions on
the frustrated J_1-J_2 kagome-Heisenberg model using the pseudo-fermion
functional-renormalization-group (PFFRG) technique. In order to treat the
off-diagonal nature of DM interactions, we develop an extended PFFRG
scheme. We benchmark this approach in parameter regimes that have
previously been studied with other methods and find good agreement of the
magnetic phase diagram. Particularly, finite DM interactions are found to
stabilize all types of non-collinear magnetic orders of the J_1-J_2
Heisenberg model (q=0, √3x√3, and cuboc orders) and shrink the extents of
magnetically disordered phases. We discuss our results in the light of the
mineral herbertsmithite which has been experimentally predicted to host a
quantum spin liquid at low temperatures. Our PFFRG data indicates that
this material lies in close proximity to a quantum critical point. In
parts of the experimentally relevant parameter regime for herbertsmithite,
the spin-correlation profile is found to be in good qualitative agreement
with recent inelastic-neutron-scattering data.

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FU Berlin
Seminar Room (I. Physik/Astrophysics)
Contact: Simon Trebst