Network coherence and imperfect superfluidity in the quantum Hall bilayer

Abstract

Recently, superfluid-like properties have been observed in bilayer quantum Hall systems, in which the effective bosonic particles are understood to be electron–hole pairs. While experimental results are highly suggestive of superfluidity, the linear response of this system remains dissipative down to the lowest available temperatures. We demonstrate that these results may be understood in terms of a unique disorder-dominated state, in which the system organizes into a coherence network, with large incoherent regions separated by quasi-one-dimensional coherent strips with vortices and antivortices at their edges. We demonstrate that this novel state supports nearly dissipationless response at non-vanishing temperatures which can explain a number of puzzling experimental results.