主讲人单位 (Speaker's Institute): 亚洲太平洋理论物理中心

邀请人 (Invited by): 张鹏鸣

时间 (Time): 星期五，2022/09/23-10：00-11：00

地点 (Location): 珠海校区天琴中心2316会议室

摘要 (Abstract): 

Fractons are particles with restricted mobility. They appear in various systems, including gapped phases in spin glasses, stabilizer code, and spin liquids, as well as gapless phases in solids, supersolids, and vortex crystals. The fractonic phases are a new kind of phase of matter that has interesting theoretical properties. For example, the gapped fractonic phases in three spatial dimensions exhibit a ground-state degeneracy that is exponential in linear system size. The gapless fractonic phases are connected to symmetric tensor gauge theory, elasticity theory, and gravity.

In recent work, we give a symmetry-based derivation of effective field theories of gapless phases with fractonic topological defects in solids and supersolids via a coset construction. The resulting theory is a tensor gauge theory that is dual to the Cosserat theory of elasticity, which reproduces conventional symmetric elasticity theory at low energies. The construction can be viewed as a dynamical realization of the inverse Higgs mechanism. We incorporate topological defects such as dislocations and disclinations, which are nontrivially related by the Bianchi identities of defect gauge fields. The origins of the fractonic properties of the systems can be traced back to the semi-direct product structure within the Euclidean group. We identified relevant Wess-Zumino terms in supersolids with broken translational symmetries, which induce quasiparticle scattering off topological defects.

主讲人简介 (Speaker's CV): 

  祁永辉，理论物理学者，本科及博士毕业于清华大学，先后在中科院理论物理研究所、北京大学、韩国汉阳大学、亚洲太平洋理论物理中心从事博士后研究。

研究兴趣主要集中在量子场理论和引力理论，包括高能基本粒子物理、引力和黑洞物理、全息流体、AdS/CFT二元论等。