Ott, Herwig

Date:  Thursday, May 3, 2018
Time:  14:30
Place:  ETH Zurich, Hönggerberg, HPF G 6
Hosts:  Tilman Esslinger/Laura Corman

Atom transport in dissipative environments

Herwig Ott
Technische Universität Kaiserslautern, Germany

Ultracold quantum gases are usually well isolated from the environment. This allows for the study of ground state properties and unitary dynamics of many-body quantum systems under almost ideal conditions. Introducing a controlled coupling to the environment “opens” the quantum system and non-unitary dynamics can be investigated. Such an approach provides new opportunities to study fundamental transport processes with ultracold atoms. I will present an experimental platform [1,2] that allows for the controlled engineering of dissipation in ultracold quantum gases by means of localized particle losses. I will then discuss two experiments involving transport of bosonic atoms at a tunneling junction. The first is the observation of negative differential conductivity [3]. The second is the appearance of a DC Josephson current in a biased tunneling junction [4]. Due to an intrinsic nonlinearity, we are able to observe bistable transport characteristics.

References
1.   T. Gericke et al., Nature Physics 4, 949 (2008)
2.   P. Würtz et al., Phys. Rev. Lett. 103, 080404 (2009)
3.   R. Labouvie et al., Phys Rev. Lett. 115, 050601 (2015)
4.   R. Labouvie et al., Phys. Rev. Lett. 116, 235302 (2016)