Chaos Along the Edge of the 2/3 Fractional Quantum Hall State

Hierarchical fractional quantum Hall states, like that at filling fraction equal to 2/3, are believed to consist of several branches of chiral edge modes [Phys. Rev. Lett. 64, 220 (1990)]. In this picture, equilibration between edge modes is necessary to explain the universal (fractionally) quantized Hall conductance [Phys. Rev. Lett. 72, 4129 (1994)]. To probe this equilibration, we study out-of-time-ordered correlation functions in the theory for the 2/3 fractional quantum Hall edge. These correlation functions provide a diagnostic of chaotic behavior in classical systems. To study the interplay of these correlation functions with electrical transport, we calculate their dependence on (short-ranged) electron-electron interactions and the interaction with disorder.