Dr. Andreas Voigt
The
"Anisotropic Spin Exchange in the Plaquette Lattice"
In
this talk I will study an anisotropic spin exchange mechanism in the so-called Plaquette lattice. The investigation of this particular
lattice is based on an experimental study of a new magnetic material Na5RbCu4(AsO4)4Cl2. The compound shows a low-temperature
magnetic transition, and recent band structure calculations revealed that an
anisotropic spin exchange mechanism might play an important role in the nature
of this transition. The pure Heisenberg-type interactions have been investigated
so far and the system shows a quantum phase transition by singlet formation. I
study the influence of the anisotropic Dzyaloshinskii-Moriya
spin exchange on the phase transition point.