CMSA Quantum Matter/Quantum Field Theory Seminar: “Mother” Effective Field Theory for Fractional Quantum Hall Systems near ν= 5/2

CMSA EVENTS

Speaker:

Juven Wang - Harvard University CMSA

We propose a unified effective field theory (EFT) of fractional quantum Hall systems near the filling fraction ν = 5/2 that flows to pertinent IR candidate phases, including non-abelian Pfaffian, anti-Pfaffian, and particle-hole Pfaffian states (Pf, APf, and PHPf). Our EFT has a 2+1d non-abelian Chern-Simons gauge theory coupled to four Majorana fermions by a discrete charge conjugation gauge field, with Gross-Neveu-Yukawa-Higgs terms. Including deformations via a Higgs condensate and fermion mass terms, we can map out a phase diagram with tunable parameters, reproducing the recently-proposed percolation picture and its gapless topological phase transitions. Our EFT sits at an energy scale above the IR phases (e.g., low energy topological field theories), but below the UV completion by electronic wavefunctions or on a lattice. Moreover, we find that Pf|APf domain walls have higher tension than domain walls in the PHPf phase. Then the former, if formed, may transition to the energetically-favored PHPf domain walls; this could, in turn, help further induce a bulk transition to PHPf. My talk is based on https://arxiv.org/abs/2005.10826, jointly with Po-Shen Hsin, Ying-Hsuan Lin, and Natalie M. Paquette; and a prior work https://arxiv.org/abs/1801.10149 with Biao Lian.

Zoom: https://harvard.zoom.us/j/977347126

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