报告题目：Evolution of the magnetic excitations and charge orders in high-Tc cuprate superconductors
报 告 人：Yingying Peng, Department of Physics, University of Illinois at Urbana-Champaign
报告时间：2018-05-28 10:00
报告地点：理科楼C302报告厅
报告摘要：The origin of unconventional superconductivity (SC) remains one of the most important challenges in condensed matter physics. Despite the diversity of materials, unconventional SC emerges nearly always in proximity to another ordered state, such as spin order and charge order, suggesting a fundamental connection between SC and charge/spin fluctuations. In this talk, I will describe the resonant inelastic X-ray scattering (RIXS) technique which has huge potential to probe several kinds of excitations at a time, from charge excitations to orbital excitations, to spin waves and lattice modes. I will show our recent RIXS studies on the magnetic excitations and charge orders in cuprates. These include: (i) The relationship between the crystal structure and the extent of hopping integrals in parent compounds, and the detrimental role of apical oxygens in superconductivity. (ii) The evolution of the magnetic excitations across the entire phase diagram of cuprates. (iii) Discovery of a re-entrant charge order outside the pseudogap regime in overdoped (Bi,Pb)2.12Sr1.88CuO6+δ, showing the ubiquitous of charge order across the entire phase diagram and inviting revision of theories that posit an essential link between the charge order and pseudogap states.
