Many-Body Chaos in the Quantum Lifshitz Model

We compute the parameters characterizing many-body quantum chaos in the 2+1D Quantum Lifshitz model with N flavors, specifically the Lyapunov exponent and butterfly velocity as a function of temperature, diffusion constant, and interaction strength. The quartic term added to break integrability gives logarithmic (in temperature) corrections to the naive expression for the Lyapunov exponent. Despite z=2 scaling, an effective temperature-dependent velocity is generated and chaos spreads ballistically.