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

G. Barontini, R. Labouvie, F. Stubenrauch, A. Vogler, V. Guarrera, and H. Ott

Phys. Rev. Lett. 110, 035302 – Published 15 January 2013

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.

Received 4 October 2012

DOI:https://doi.org/10.1103/PhysRevLett.110.035302

Authors & Affiliations

G. Barontini^*, R. Labouvie, F. Stubenrauch, A. Vogler, V. Guarrera, and H. Ott

Research Center OPTIMAS and Fachbereich Physik, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany

^*barontini@physik.uni-kl.de

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand

Issue

Vol. 110, Iss. 3 — 18 January 2013

Reuse & Permissions

Access Options

Author publication services for translation and copyediting assistance advertisement

Images

Figure 1
(a) The electrons locally collide with the atoms constantly dissipating the BEC. (b) Temporal resolved signal from the ion detector. The bin size is $1 μ s$ . Points are experimental data averaged over 1800 experimental repetitions, while the solid curve is the numerical simulation (see text). After 5 ms we typically collect $≃ 450$ ions.Reuse & Permissions
Figure 2
Number of ions collected within the first 5 ms of continuous dissipation on a BEC as a function of the EB current $I$ . The three panels report the data obtained with $w = 127 (5)$ , 17(7), and 212(8) nm, from left to right. Each data point is the average over 75 experimental repetitions. The error bars are mainly due to shot-to-shot fluctuations in the overall ion detection efficiency. The solid lines are the number of dissipated atoms resulting from the numerical simulations (see text). Please note that in the sum the initial decay visible in Fig. 1b is also included. The scale on the top reports the strength of the imaginary potential $U / \bar{h} = γ (0) / 2$ corresponding to the measured current.Reuse & Permissions
Figure 3
(a) Theoretical curves of the number of ions produced in 5 ms as a function of $U / \bar{h}$ solving Eq. (1) for different values of $w$ . The values of $U_{M}$ obtained using the approximate expression given in the text are shown as open diamonds over the corresponding curves. (b) Number of ions measured after 5 ms of dissipation for a thermal cloud as a function of the EB current, with $w = 170 (7) nm$ . The solid line is the result of the corresponding numerical simulation using the molecular dynamics method. (c) Comparison between the theoretical curves of the number of produced ions as a function of $I$ for the BEC and the corresponding (see text) classical analogue [ $w = 170 (7) nm$ ].Reuse & Permissions
Figure 4
(a) Temporal resolved signal of the arrival time of the ions on the ion detector for different values of the EB current $I$ for $w = 170 (7) nm$ . In order to enhance readability the data have been plotted with a binning of $50 μ s$ . The insets (b) and (c) show the integrals of the signal in the shaded areas (the first $5 μ s$ and from 1 to 5 ms, respectively) for different values of $I$ together with the theoretical calculations obtained solving Eq. (1). (d) Points: scanning electron microscopy image of the BEC profile along the weak confining axis of the optical trap. The profile is the integrated column density along the direction of propagation of the EB. The scan is made after 1 ms of dissipation. The EB parameters are $I = 150 nA$ and $w = 106 (5) nm$ . The depletion of the density is visible in the origin, i.e., in the center of the BEC. The solid line is the profile obtained numerically solving Eq. (1).Reuse & Permissions

Physical Review Letters