Sub-ballistic growth of Rényi entanglement in quantum systems with diffusive transport – Dr. Curt von Keyserlingk, University of Birmingham

November 21, 2019 @ 2:15 pm – 3:15 pm
TCM Seminar Room
Cavendish Laboratory
Katarzyna Macieszczak

There is much current interest in uncovering the universal features of entanglement growth and information spreading in quantum systems. I will present a new universal result: Following a quench in a generic system with diffusive transport, the higher Rényi entropies grow diffusively in time while the von Neumann entropy grows linearly. This result has import for on-going efforts to measure the growth of entanglement entropy in real quantum systems. Our current scalable experimental protocols target Rényi entropies, which were believed to mimic the von Neumann entropy—which is the quantity of greatest theoretical interest and the one we would ideally be able to measure. Our result shows that this widely held belief is untrue: higher Rényi entropies grow in a qualitatively different fashion to the von Neumann entropy.

T. Rakovszky, F. Pollmann, and C. W. von Keyserlingk, Phys. Rev. Lett. 122, 250602 (2019).