Effects of electron correlations on transport properties of iron at Earth’s core conditions

摘要: Based on first-principles resistivity calculations, it was recently concluded that the thermal conductivity of iron in Earth’s core too high to sustain convection, thus invalidating such geodynamo models; new calculations including electron correlations find electron–electron scattering is comparable electron–phonon at temperatures iron, doubling expected resistivity, and reviving conventional models. Numerical based density functional theory have been used predict pressure temperature conditions Earth's substantially higher than previously thought, point would be difficult with convection. But now Peng Zhang et al. combined a self-consistent dynamical mean-field theory, temperatures. They lower for compared earlier which once again consistent convection driving geodynamo. magnetic field has thought arise from molten alloy outer core, but recent suggested support convection1,2,3,4, resulting investigation chemically driven convection5,6. These were scattering. Here we apply plus (DFT + DMFT)7 scattering, bringing into agreement experiments solving transport problem core. The dynamo picture safe. We d electrons important transition metals, contrast textbook analyses since Mott8,9, 4s contributions are negligible, numerous models over fifty years. DFT+DMFT method should applicable other high-temperature systems where important.