Pairing gap and in-gap excitations in trapped fermionic superfluids

Science

Volumn 305, Issue 5687, 2004, Pages 1131-1133

  Kinnunen, J ^a   Rodriguez M ^a   Torma P ^a  

^a UNIVERSITY OF JYVÄSKYLÄ   (Finland)

Author keywords

[No Author keywords available]

Indexed keywords

FERMI LEVEL; LASER BEAM EFFECTS; SPECTRUM ANALYSIS; SUPERFLUID HELIUM;

FESHBACH-RESONANCE; PAIRING GAPS;

FERMIONS;

GAS; SPECTROSCOPY;

ARTICLE; CELL MEMBRANE FLUIDITY; EXCITATION; FERMION; FESHBACH RESONANCE; FLUID FLOW; GAS FLOW; IN GAP EXCITATION; NUCLEAR MAGNETIC RESONANCE; PAIRING GAP EXCITATION; PRIORITY JOURNAL; RADIOFREQUENCY; SPECTROSCOPY; SUPERCONDUCTOR; TEMPERATURE MEASUREMENT;

EID: 4143139632     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.1100782     Document Type: Article

References (25)

1. A. J. Leggett, Modern Trends in the Theory of Condensed Matter (Springer-Verlag, Berlin, 1980), p. 13.
2. P. Nozières, S. Schmitt-Rink, J. Low Temp. Phys. 59, 195 (1985).
3. C. A. Regal, M. Greiner, D. S. Jin, Phys. Rev. Lett. 92, 040403 (2004).
4. M. Bartenstein et al., Phys. Rev. Lett. 92, 120401 (2004).
5. M. W. Zwierlein et al., Phys. Rev. Lett. 92, 120403 (2004).
6. J. Kinast, S. L. Hemmer, M. E. Gehm, A. Turlapov, J. E. Thomas, Phys. Rev. Lett. 92, 150402 (2004).
7. M. Bartenstein et al., Phys. Rev. Lett. 92, 203201 (2004).
8. C. Chin et al., Science 305, 1128; published online 22 July 2004 (10.1126/science.1100818).
9. P. Törmä, P. Zoller, Phys. Rev. Lett. 85, 487 (2000).
10. G. M. Bruun, P. Törmä, M. Rodríguez, P. Zoller, Phys. Rev. A. 64, 033609 (2001).
11. J. Kinnunen, M. Rodríguez, P. Törmä, Phys. Rev. Lett. 92, 230403 (2004).
12. C. A. Regal, D. S. Jin, Phys. Rev. Lett. 90, 230404 (2003).
13. S. Gupta et al., Science 300, 1723 (2003).
14. M. Holland, S. J. J. M. F. Kokkelmans, M. L. Chiofalo, R. Walser, Phys. Rev. Lett. 87, 120406 (2001).
15. E. Timmermans, K. Furuya, P. W. Milonni, A. K. Kerman, Phys. Lett. A 285, 228 (2001).
16. Y. Ohashi, A. Griffin, Phys. Rev. Lett. 89, 130402 (2002).
17. J. Stajic et al., Phys. Rev. A. 69, 063610 (2004).
18. Materials and methods are available as supporting material on Science Online.
19. M. L. Chiofalo, S. J. J. M. F. Kokkelmans, J. N. Milstein, M. J. Holland, Phys. Rev. Lett. 88, 090402 (2002).
20. The pronounced free-atom peak at the zero detuning clearly reflects the strong dependence of the order parameter on density and the trapping potential. In the case of a very smooth density dependence of the energy gap, one would expect simply a broadening of the pair peak. Such a behavior was actually observed in the experiments probing mean fields (12, 13). There, only one peak was observed and the effect of the trapping potential was a considerable broadening of the peak.
21. Note that because not only energy but also momentum is exactly conserved in the transfer process, these particles cannot be transferred at zero detuning. This is in contrast to superconductor-normal metal junctions where thermal quasiparticle currents flow freely for below-gap voltages.
22. M. A. Baranov, JETP Lett. 70, 396 (1999).
23. The precise relation between T′ and T at the unitarity limit is not known, but the analysis in the case of a noninteracting Fermi gas (24) supports this argument.
24. L. D. Carr, G. V. Shlyapnikov, Y. Castin, Phys. Rev. Lett. 92, 150404 (2004).
25. We thank C. Chin and R. Grimm for a stimulating exchange of results and very useful discussions. We acknowledge financial support from the Academy of Finland (Project Nos. 53903 and 205470) and the Emil Aaltonen Foundation.