Observation of the Pairing Gap in a Strongly
Interacting Fermi Gas

Institut für Experimentalphysik,
University of Innsbruck, and
Austrian Academy of Sciences,
Innsbruck, Austria

We observe the fermionic pairing gap of ultracold, strongly interacting 6Li atoms. Our measurements are based on radio-frequency (RF) spectroscopy. The broad signal from paired-atoms (marked by the arrows in the figure) is located at higher frequency than the sharp signal from unpaired atoms. The excess energy (gap energy) is required to break the pairs. This observation can possibly provide new insights into the properties of the superconducting gap in high-Tc superconductors. Our results are published on July 22th 2004 in Science Express.

Science 305, 1128 (2004); published online 22 July 2004 (10.1126/science.1100818). cond-mat/0405632

See also the accompanying theory article by P. Törmä's group in the same issue of Science Express (to dowload this article click here!!!).

Emergence of the pairing gap in a strongly interacting Fermi gas as the temperature of the sample is lowered. (TF = 2.25K)
our trapping apparatus


The Team

A collaboration between the Institute of Experimental Physics, Innsbruck University and the Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences

standing from left to right:

  • Johannes Hecker Denschlag (staff scientist)
  • Cheng Chin (Lise-Meitner fellow of the FWF)
  • Rudi Grimm (group leader)
  • Markus Bartenstein (PhD student)
  • Alexander Altmeyer (PhD student)

sitting from left to right:

  • Stefan Riedl (Diploma student)
  • Selim Jochim (PhD student)


We are supported by the Austrian Science Fund (Fonds zur Förderung der wissenschaftlichen Forschung, FWF) in the frame of the Spezialforschungsbereich F15 "Control and Measurement of Coherent Quantum Systems" and by the European Union in the frame of the Cold Molecules TMR Network.


last change: 05-12-15 by JH