Open Positions



We are always interested in prospective PhD students as well as postdocs. Also, students are encouraged to apply for semester/bachelor/master projects at any time. For information or application, please contact Tilman Esslinger and/or Tobias Donner.



Postdoc Opening


Quantum Simulation of Devices

Transport of fermionic lithium atoms through mesoscopic structures shaped by laser light

Two atomic reservoirs are smoothly connected by a mesoscopic channel, forming a two-terminal configuration. In this rather unique set-up we measure conductances of small quantum gas samples, such as two-dimensional films and quantum wires, often with direct analogies to quantum electronic devices.

Employing ultrahigh-resolution microscope objectives and a Digital Micromirror Device we generate almost arbitrary optical potentials for the lithium gas, ranging from single obstacles to optical lattices. This flexibility together with the unique tunability of interactions in lithium enables us to probe mesoscopic transport of strongly correlated matter.

In a recent study we measured quantized conductance through a spin-selective atomic point contact. A strongly focused laser (red in the upper figure) acts as an optical tweezer or anti-tweezer, i.e. it is tuned to repel one atomic state (blue) and to attract the other (orange). Although the light is close to resonance, we are able to observe quantized plateaus of conductance after measuring for several seconds without detrimental heating. This also gives us the possibility of detecting minute variations in the number of atoms in the channel, seeing the distance between the conductance plateaus being modified by a change of only two particles.

In another study we created band and correlated insulators of cold fermions in a mesoscopic lattice structure, which connected the two reservoirs. For weak interactions we witnessed the emergence of a band- insulating phase by observing a conductance gap. As interactions are tuned from weakly to strongly attractive, we discover that this insulating state persists, hinting at the presence of a Luther-Emery liquid, a phase predicted uniquely for one-dimensional structures.

The goal of the project is to identify and characterize non-equilibrium phenomena in strongly correlated many-body physics. The research is carried out in a small team and a strong background in experimental quantum gas physics as well as in theoretical many-body physics would be welcome. Starting time and duration of the PostDoc position are flexible.



References:
[1] M. Lebrat, S. Häusler, P. Fabritius, D. Husmann, L. Corman, and T. Esslinger, Quantized Conductance through a Spin-Selective Atomic Point Contact. Phys. Rev. Lett. 123, 193605 (2019).
[2] M. Lebrat, P. Grišins, D. Husmann, S. Häusler, L. Corman, T. Giamarchi, J.-P. Brantut, and T. Esslinger, Band and Correlated Insulators of Cold Fermions in a Mesoscopic Lattice. Phys. Rev. X 8, 011053 (2018)

Please contact:
Prof. Tilman Esslinger
esslinger@phys.ethz.ch
ETH Zurich, Otto-Stern-Weg 1, CH-8093 Zürich