Hall 123

Frustrated Magnetism on Hollandite lattice

Saptarshi Mandal

ICTP

In this talk we describe the magnetism on Hollandite lattice.
Hollandite lattice is a variant of triangular lattice and is
the lattice of alpha-MnO2 material. We begin with a brief
introduction to frustrated magnetism and outline the general
methods to describe it. Followed by it, we present a model of
interacting classical Heisenberg spins on Hollandite lattice
and describe its ground state in the parameter space of the model
parameter. It is shown that, in general, the ground state is
described by four different helical spin configuration, depending
on the relative sign and strength of model parameters. By calculating the
susceptibilities and comparing with experimental results, we connect
some of the ground state spin configuration to that of the alpha-MnO2 materials.
We end with a discussion of lowest excitations of the spins and the possible
appearance of a spin-glass phase in the presence of disorder in the
model parameter.