杨昆教授学术报告

报告时间：6月21日下午2:00

报告地点：望江校区东区二教102。

报 告 人：杨昆教授，美国国家强磁场实验室、佛罗里达州立大学

两个报告，每个45分钟

报告一：Condensed Matter Physics: What Happened Since Ashcroft/Mermin and Where Is It Going?

摘要：

The classic textbook by Ashcroft and Mermin, named Solid State Physics, has dominated education of graduate students in the field of condensed matter physics since its publication in 1976. Tremendous progress has been made in our field over the past 40 years, and a modern textbook replacing this aging classic is in urgent need. In this informal discussion I will report our on-going attempt to meet this need, and seek comments and advices from the audience on our work.

报告二：Interplay of Topology and Geometry in Fractional Quantum Hall Liquids

摘要：

Fractional Quantum Hall Liquids (FQHL) are the ultimate strongly correlated electron systems, and the birth place of topological phase of matter. Early theoretical work has emphasized the universal or topological aspects of quantum Hall physics. More recently it has become increasingly clear that there is very interesting bulk dynamics in FQHL, associated with an internal geometrical degree of freedom, or metric. The appropriate quantum theory of this internal dynamics is thus expected to take the form of a “quantum gravity”, whose elementary excitations are spin-2 gravitons. After briefly reviewing the topological aspect of FQHL, I will discuss in this talk how to couple and probe the presence of this internal geometrical degree of freedom experimentally in the static limit [1], and detect the graviton excitation in a spectroscopic measurement [2]. Comparison will be made with recent experimental [3] and numerical [4] work.

Reference:

[1] Kun Yang, Geometry of compressible and incompressible quantum Hall States: Application to anisotropic composite-fermion liquids, Phys. Rev. B 88, 241105 (2013).

[2] Kun Yang, Acoustic Wave Absorption as a Probe of Dynamical Gravitational Response of Fractional Quantum Hall Liquids, Phys. Rev. B 93, 161302 (2016).

[3] Insun Jo, K. A. Villegas Rosales, M. A. Mueed, L. N. Pfeiffer, K. W. West, K. W. Baldwin, R. Winkler, Medini Padmanabhan, M. Shayegan, Transference of Fermi Contour Anisotropy to Composite Fermions, arXiv:1701.06684.

[4] Matteo Ippoliti, Scott D. Geraedts, R. N. Bhatt, Numerical Study of Anisotropy in the Composite Fermi Liquid, arXiv:1701.07832.