Sebastian Deffner: Nonlinear speed-ups in ultracold quantum gases

Abstract

Estimating the maximal rate with which quantum states can change is of fundamental importance in virtually all areas of quantum physics. Upper bounds on this rate have become known as Quantum Speed Limits, which can be understood as rigorous generalizations of Heisenberg’s uncertainty relation for energy and time. In this talk, I will be analyzing Quantum Speed Limits for ultracold Bosonic gases that are well-described by the Gross-Pitaevskii equation. I will demonstrate that the nonlinear term permits quantum states to evolve faster than in linear media. From a practical point of view, this observation may be exploited for accelerated quantum communication in nonlinear optical fibers.