Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/76435
Title: Polarized neutron scattering signatures of classical spin ice
Authors: Goh, Jeremy Swee Kang
Keywords: DRNTU::Science::Physics::Electricity and magnetism
Issue Date: 2019
Abstract: Almost a decade ago, it was proposed by Fennell et al. that polarized neutron scattering could expose the dipolar spin correlations in the classical spin ice Ho2Ti2O7, in which its sharp, distinctive “pinch-point” signatures would appear exclusively in the spin-flip (SF) neutron scattering channel, and not in the non-SF (NSF) channel. In the same work, they showed via Monte Carlo simulations that the NSF of the nearest-neighbour (NN) spin ice, excluding the magnetic form factor, is completely featureless (i.e., no dispersions) in the (hhl) scattering plane. However, no explanation was offered by the authors for this particular observation, and this has been largely overlooked in the literature since then. In this thesis, we endeavoured to understand the origins of NSF scattering patterns (or rather, lack thereof) for classical spin ice using a combination of analytical techniques and numerical simulations. We propose two ways of understanding this phenomenon: 1) as a manifestation of the flat bands within the framework of the large-n approximation, or 2) vanishing real space correlations between chains in the pyrochlore lattice. The relevance of the flat bands to featureless NSF is exposed via analysis of the large-n matrix, while the latter is supported by Monte Carlo simulation results.
URI: http://hdl.handle.net/10356/76435
Schools: School of Physical and Mathematical Sciences 
Fulltext Permission: restricted
Fulltext Availability: With Fulltext
Appears in Collections:SPMS Student Reports (FYP/IA/PA/PI)

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