MS26-P01 Polarisation via local ordering mechanismsSystems containing correlated disorder are becoming more and more prevalent in materials science.1 Thus understanding and exploring the disorder-property relationship is becoming of greater importance. In our work2 we focussed on how aperiodic systems could lead to a macroscopic polarisation. Using classical Monte Carlo simulations, we study a simple statistical mechanical model from local displacements on the square and cubic lattices. Our model contains two key ingredients: a Kitaev-like orientation-dependent interaction between nearest neighbours, and a steric term that acts between next-nearest neighbours. Taken by themselves, each of these two ingredients drives its own form of local ordering to a non-polar disordered phase with a manifold of degenerate ground states. These phases are incapable of driving long-range symmetry breaking, despite the presence of a broad feature in the corresponding heat capacity functions. Instead each ingredient results in a "hidden" transition on cooling to two distinct types of local order. Remarkably, their intersection i.e. the ground state when both interaction contributions are invoked leads to a disordered, but polar, phase which has conceptual parallels to tetragonal BaTiO3 or KNbO3.3 These key ingredients could potentially be utilised in future material designReferences:
 Damasceno, P. F. et al. (2012). Science 337, 453–457.
 Wolpert, E. H. et al. (2018). Phys. Rev. B, 97, 134106.
 Senn, M. S. et al. (2016). Phys. Rev. Lett. 116, 207602.Keywords: polarisation, correlated disorder