Cavity-Coupled Quantum Hall Hydrodynamics and the Quantum Reactance Effect
When a quantum Hall liquid is placed inside an electromagnetic cavity, coupling to the quantized cavity field leaves the topological Hall conductivity quantized but induces a second-order quantum reactance that modifies the longitudinal AC conductivity, most strongly transverse to the cavity polarization. The cavity also couples to collective excitations, shifting the Kohn-mode frequency. A hydrodynamic effective theory captures these effects universally for both integer and fractional states and explains why topological transport survives cavity-induced long-range interactions.
Cavity Quantum Hall Hydrodynamics Gabriel Cardoso,1, ∗Liu Yang,1, 2, ∗Thors Hans Hansson,3, † and
This paper develops a hydrodynamic theory of quantum Hall (QH) liquids coupled to the quantized electromagnetic field of an optical resonance cavity. In the regime where cavity photons do not drive i…