Entanglement entropy production and the Kolmogorov-Sinai rate

The rate of entropy production in a classical dynamical system is characterized by the Kolmogorov-Sinai entropy rate given by the sum of all positive Lyapunov exponents of the system. I will present a quantum version of this result valid for bosonic systems with unstable quadratic Hamiltonians: the entanglement entropy of squeezed coherent states grows linearly for large times, with a rate determined by the Lyapunov exponents and the choice of the subsystem. I will discuss the application of this result to quantum field theory and its conjectured implications for the behaviour of chaotic quantum systems prepared in a semiclassical state.

*Local: Sala Jayme Tyomno