报告题目: |
ARPES studies on Bi-2212 high Tc superconductors |
报告人: |
Inna Vishik |
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Stanford University
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报告时间: |
2009-12-16 16:00 |
报告地点: |
物理系2315报告厅 |
主办单位: |
物理系 |
简介: |
报告摘要：Bi2Sr2CaCu2O8+x (Bi-2212) is a compound which is amenable to study by angle-resolved photoemission spectroscopy (ARPES) because it cleaves easily, has sharp lineshapes, and has relevant energy scales which are accessible to modern instruments. Despite the large volume of previous ARPES work on this system, Bi-2212 continues to provide insights about the high-temperature cuprate superconductors. I will discuss two of our recent experiments. The first work focuses on the discrepancy between recent quasiparticle interference STM experiments and ARPES data: while the former sees evidence of interfering quasiparticles over a limited region of the Fermi surface, ARPES sees sharp quasiparticle peaks all around the Fermi surface. I will discuss the ubiquity of sharp quasiparticles in ARPES data, and explain why they may not contribute to QPI in all regions of momentum space. Second, I will discuss our recent experiments using laser-based ARPES, which allows for superior resolution and signal strength. Laser ARPES is able to resolve a small kink at very low energies in the nodal dispersion of Bi-2212, and the doping dependence of this kink has implications for understanding thermodynamic measurements. |
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