报告题目: |
Nematic phase and dynamical Geometry in Quantum Hall family |
报告人: |
Yizhi You |
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University of Illinois at Urbana-Champaign
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报告时间: |
2014-06-05 15:00 |
报告地点: |
Conference Hall 322, Science Building, Tsinghua University |
主办单位: |
高等研究院 |
简介: |
We derive and study the effective field theories of isotropic-nematic quantum phase transitions of
Chern insulators and FQH states, where the nematic orders modify the local geometry tensor and
emerge as a dynamical frame field.
In both cases, we demonstrate that the low-energy theory of nematic order parameter has z=2
dynamics due to a Berry phase term of the nematic order, which is related with some unique
geometry property in parity and TRS broken states. We present a fermionic Chern-Simons gauge
theory for a FQH fluid with attractive quadrupolar interactions which trigger a transition to a
nematic phase. By investigating the excitation spectrum at RPA level, we demonstrate that at the
quantum phase transition the energy gap of Girvin-MacDonald-Plazman mode condenses at zero
momentum.
The vortex of the nematic field contributes to the spin connection which minimal couples with the
gauge field. The gravitational term of the nematicity indicates the fractional statistics nature of
nematic vortex. Thus, the interplaybetween nematic vortex and FQH quasiparticle would give rise
to new exotic phenomenon. |
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