Superconducting Atomchip

Superconductivity and ultracold atoms follow the same physics. However, experimentally, they don’t share the same environment.
Superconductors require cryostats down to mK with UHV and absence of light while Ultracold atoms need light (Magneto-Optical Trap) and usually a warm vapor from which the atoms are trapped from. Combining both technologies is not as straight-forward as it may seem [1].

 
Experimental Setup Rendering

In our lab, we have constructed a magnetic conveyor belt type of transport to bring ultracold Rb87 atoms into a cryogenic environment [2]. The magnetic transport is highly efficient and the design is such that there is a rapid turn-around time for maintenance and/or upgrade. The setup allows us to bring 10^8 thermal atoms at about 300uK into a 4K cryostat. The atoms are subsequently reloaded into a superconducting atomchip formed by a Niobium wire.

 
Meissner Trap outlining the chip (left) and the Sapphire substrate with the chip wire (right)

The entire experiment opens different possibilities with ultracold atoms in cryogenic environment. Ultracold atoms can be used to probe and study superconducting surfaces [3-6]. The cryogenic environment also allows using ultracold atoms as a quantum memory for hybrid quantum systems with a superconducting microwave resonator [7-8].

 
Reloading sequence (left) and the corresponding absorption imaging of the atoms (right)


Rendering of ultracold atoms on top a superconducting microwave resonator

References:

    1. Haslinger S. et al.: Electron beam driven alkali metal atom source for loading a magneto-optical trap in a cryogenic environment. Appl. Phys. B 102, 819 (2011) http://link.springer.com/article/10.1007%2Fs00340-011-4447-x
    2. Magnetic conveyor belt transport of ultracold atoms to a superconducting atomchip. Stefan Minniberger , Fritz Diorico, Stefan Haslinger, Christoph Hufnagel, Christian Novotny, Nils Lippok, Johannes Majer, Christian Koller, Stephan Schneider and Jörg Schmiedmayer. Applied Physics B, Lasers and Optics, arXiv:1311.3155 http://link.springer.com/article/10.1007%2Fs00340-014-5790-5/fulltext.html
    3. T, Nirrengarten, A. Qarry, C. Roux, A. Emmert, G. Nogues, M. Brune, J.-M. Raimond, and S. Haroche, Realizeation of a Superconducting Atom Chip, PRL 97, 200405 (2006)
    4. Imai, H., & Inaba, K. (2014). Bose – Einstein condensate on a persistent-supercurrent atom chip, Appl. Phys. B. (2014) 116:821–829. doi:10.1007/s00340-014-5768-3
    5. Romero-Isart, O., Navau, C., Sanchez, A., Zoller, P., & Cirac, J. I. (2013). Superconducting Vortex Lattices for Ultracold Atoms. Physical Review Letters, 111(14), 145304. doi:10.1103/PhysRevLett.111.145304
    6. P. Weiss, M. Knufinke, S. Bernon, D. Bothner, L. Sárkány, C. Zimmermann, R. Kleiner, D. Koelle, J. Fortágh, H. Hattermann, Sensitivity of ultracold atoms to quantized flux in a superconducting ring, arXiv:1502.01858
    7. Verdú, J., Zoubi, H., Koller, C., Majer, J., Ritsch, H., & Schmiedmayer, J. (2009). Strong Magnetic Coupling of an Ultracold Gas to a Superconducting Waveguide Cavity. Physical Review Letters, 103(4), 043603. doi:10.1103/PhysRevLett.103.043603
    8. Haslinger, S., Amsüss, R., Hufnagel, C., Koller, C., Lippok, N., Schramböck, M., … Innsbruck, H. R. U. (n.d.). Hybrid Quantum Systems : Integrating Atomic and Solid-State Qubits Circuit Quantum-Electrodynamics Superconducting Microwave Resonator Ultracold Atoms in a Cryogenic Environment Electron beam assisted Alkali Metal Source.

Team
Fritz Diorico, PhD Student (Right), Stefan Minniberger, PhD Student (Midle),  and Jörg Schmiedmayer, Principal Investigator (Left)

Not in photo: MSc Students: Benedikt Gerstenecker, Thomas Weigner, Naz Shokrani

IMG_9295

Open positions
Yes, we do look for motivated phd, diploma and project students
Just contact Fritz, Stefan or Jörg for inquiries or to arrange a visit.

Publications
1. Haslinger S. et al.: Electron beam driven alkali metal atom source for loading a magneto-optical trap in a cryogenic environment. Appl. Phys. B 102, 819 (2011)
http://link.springer.com/article/10.1007%2Fs00340-011-4447-x
2. Magnetic conveyor belt transport of ultracold atoms to a superconducting atomchip
Stefan Minniberger , Fritz Diorico, Stefan Haslinger, Christoph Hufnagel, Christian Novotny, Nils Lippok, Johannes Majer, Christian Koller, Stephan Schneider and Jörg Schmiedmayer
Applied Physics B, Lasers and Optics, arXiv:1311.3155
http://link.springer.com/article/10.1007%2Fs00340-014-5790-5/fulltext.html