Controlling the Dynamics of an Open Many-Body Quantum System with Localized Dissipation

TLDR

Because of the high degree of control on every parameter, our system is a promising candidate for the engineering of fully governable open quantum systems. The study experimentally investigates how a localized dissipative potential, realized by an electron beam on a Bose‑Einstein condensate, affects the macroscopic matter wave. The experiment employs an electron‑beam–induced localized dissipation on a BEC, varying beam parameters, monitoring the resulting dynamics, and comparing the observations to a simple theoretical model. The measurements reveal a paradoxical loss behavior where increasing dissipation beyond a critical strength reduces atom loss, a result that agrees with theory and links the dynamics to a generalized Zeno effect.

Abstract

We experimentally investigate the action of a localized dissipative potential on a macroscopic matter wave, which we implement by shining an electron beam on an atomic Bose-Einstein condensate (BEC). We measure the losses induced by the dissipative potential as a function of the dissipation strength observing a paradoxical behavior when the strength of the dissipation exceeds a critical limit: for an increase of the dissipation rate the number of atoms lost from the BEC becomes lower. We repeat the experiment for different parameters of the electron beam and we compare our results with a simple theoretical model, finding excellent agreement. By monitoring the dynamics induced by the dissipative defect we identify the mechanisms which are responsible for the observed paradoxical behavior. We finally demonstrate the link between our dissipative dynamics and the measurement of the density distribution of the BEC allowing for a generalized definition of the Zeno effect. Because of the high degree of control on every parameter, our system is a promising candidate for the engineering of fully governable open quantum systems.