Lattice dynamical, electronic, and structural properties of complex metals at extreme conditions

点击翻译按钮获取中文摘要

I aim to exploit my expertise in optical and x-ray spectroscopy, x-raydiffraction, and first-principles computations to gain fundamental newinsight into the physical properties of complex elemental metals atextreme conditions in pressure and temperature. The research proposed hereconcerns the physics of elemental metals (such as Cs, Rb, Ba, Te) withcomplex crystal structures, where we have witnessed, in recent years, analmost revolutionary change in our understanding of the structural andbonding properties in elemental crystals under pressure. While there hasbeen as series of discoveries of remarkably and unexpectedly complexcrystal structures in elemental solids, very little is known about thephysical properties of these phases.I propose to make detailed studies of the lattice dynamical and electronicproperties of complex phases of elemental metals at extreme conditions inpressure and temperature. The experimental investigations will be based ona combination of spectroscopic techniques / optical Raman spectroscopy,inelastic x-ray scattering spectroscopy, as well as diffuse x-rayscattering analysis /, and will be closely coupled with computationalwork. X-ray diffraction investigations of structural aspects willcomplement the spectroscopic studies where needed. I will investigate thelattice dynamics of the remarkably complex and often incommensuratestructures that have been found in K, Rb, Sr, Ba, Sc, As, Sb, Bi, S, Se,Te and Ga at high pressures. In addition to studies of phonon softeningand other anomalies in their phonon dispersion curves, I will embark on anambitious programme of studies on their electronic properties. I willinvestigate the superconducting gap in superconducting phases to gainunderstanding of the pairing mechanism, and aspire to detect andcharacterise pseudogaps in the electronic excitation spectra. Altogether,this research aims at gaining fundamental new insight in the behaviour andproperties of elemental metals at high pressure and at developing acoherent picture of the mechanisms that lead to the unexpectedly frequentformation of complex crystal structures under pressure.