Quantum matter in high magnetic fields

Abstract:

Calcium silicate perovskite (CaSiO3) is one of the major mineral components of the lower mantle, but has been the subject of relatively little work compared to the more abundant Mg-based materials. One of the major problems related to CaSiO3 that is still the subject of research is its crystal structure under lower mantle conditions – a cubic Pm¯3m structure is accepted in general, but some have suggested that lower-symmetry structures may be relevant. In this work, we use a fully first principles vibrational self-consistent field (VSCF) method to perform high accuracy anharmonic vibrational calculations on several candidate structures at a variety of points along the geotherm near the base of the lower mantle, in order to investigate the stability of the cubic structure and related distorted structures. Our results show that the cubic structure is the most stable throughout the lower mantle, and that this result is robust against the effects of thermal expansion.

Abstract:

The data reflect experimental transport and tunnel diode oscillator measurements collected in zero field or in magnetic fields either in Oxford or at the NHMFL Tallahassee Florida. Measurements were performed at different applied pressuresusing a piston pressure cell. The data set contain raw data plotted in Figures of the manuscript arXiv:1902.11276 (https://arxiv.org/abs/1902.11276).