Theory of Electromagnons in CuO.
Physical review letters 114:19 (2015) 197201
Abstract:
We develop a theory of electromagnons in CuO by combining a symmetry analysis based on irreducible corepresentations, ab initio calculations, and simulations of spin dynamics using a model Hamiltonian and the Landau-Lifshitz-Gilbert equation. We show that the electromagnon measured in [Jones et al., Nat. Commun. 5, 3787 (2014)] with the electric field along the [101] direction originates from a magnetoelectric coupling mediated by Dzyaloshinskii-Moriya interactions and consists of a rigid rotation of the Cu spins around the axis defined by the electric field. Furthermore we predict the existence of a second electromagnon originating from exchange striction and coupled to electric fields along the [010] direction in the AF2 phase.Non-ferroelectric nature of the conductance hysteresis in CH3NH3PbI3 perovskite-based photovoltaic devices
Applied Physics Letters AIP Publishing 106:17 (2015) 173502
The contribution of Diamond Light Source to the study of strongly correlated electron systems and complex magnetic structures.
Philosophical transactions. Series A, Mathematical, physical, and engineering sciences 373:2036 (2015) 20130148
Abstract:
We review some of the significant contributions to the field of strongly correlated materials and complex magnets, arising from experiments performed at the Diamond Light Source (Harwell Science and Innovation Campus, Didcot, UK) during the first few years of operation (2007-2014). We provide a comprehensive overview of Diamond research on topological insulators, multiferroics, complex oxides and magnetic nanostructures. Several experiments on ultrafast dynamics, magnetic imaging, photoemission electron microscopy, soft X-ray holography and resonant magnetic hard and soft X-ray scattering are described.First-principles study of structurally modulated multiferroic CaMn7O12
Physical Review B American Physical Society (APS) 91:6 (2015) 064422
The roles of chirality and polarity in novel multiferroics: MnSb 2 O 6 and Cu 3 Nb 2 O 8
Acta Crystallographica Section A: Foundations and advances International Union of Crystallography (IUCr) 70:a1 (2014) c386-c386