Space Science Reviews

, Volume 148, Issue 1–4, pp 225–232 | Cite as

Atom-Based Test of the Equivalence Principle

  • Sebastian FrayEmail author
  • Martin Weitz
Open Access


We describe a test of the equivalence principle with quantum probe particles based on atom interferometry. For the measurement, a light pulse atom interferometer based on the diffraction of atoms from effective absorption gratings of light has been developed. A differential measurement of the Earth’s gravitational acceleration g for the two rubidium isotopes 85Rb and 87Rb has been performed, yielding a difference Δg/g=(1.2±1.7)×10−7. In addition, the dependence of the free fall on the relative orientation of the electron to the nuclear spin was studied by using atoms in two different hyperfine states. The determined difference in the gravitational acceleration is Δg/g=(0.4±1.2)×10−7. Within their experimental accuracy, both measurements are consistent with a free atomic fall that is independent from internal composition and spin orientation.


Quantum mechanics Gravity Equivalence principle Atom interferometer 


  1. J. Audretsch, U. Bleyer, C. Lämmerzahl, Phys. Rev. A 47, 4632 (1993) CrossRefADSGoogle Scholar
  2. See, e.g., P. Berman, Atom Interferometry (Academic Press, San Diego, 1997). Google Scholar
  3. P. Cladé, S. Guellati-Khélifa, F. Nez, F. Biraben, Phys. Rev. Lett. 102, 240402 (2009) CrossRefADSGoogle Scholar
  4. See, e.g.: W. Ertmer et al., Exp. Astron. 23, 611 (2009) CrossRefADSGoogle Scholar
  5. S. Fray, C. Alvarez Dies, T.W. Hänsch, M. Weitz, Phys. Rev. Lett. 93, 240404 (2004) CrossRefADSGoogle Scholar
  6. T.L. Gustavson, P. Bouyer, M.A. Kasevich, Phys. Rev. Lett. 78, 2046 (1997) CrossRefADSGoogle Scholar
  7. T.L. Gustavson, A. Landragin, M.A. Kasevich, Class. Quantum Gravity 17, 2385 (2000) zbMATHCrossRefADSGoogle Scholar
  8. J.M. Hensley et al., J. Sci. Instrum. 70, 2735 (1999) CrossRefADSGoogle Scholar
  9. H. Hinderthür et al., Phys. Rev. A 56, 2085 (1997) CrossRefADSGoogle Scholar
  10. C.H. Hsieh et al., Mod. Phys. Lett. A 4, 1597 (1989) CrossRefADSGoogle Scholar
  11. C. Lämmerzahl, in Proceedings of the International School of Cosmology and Gravitation, Course XV, ed. by P.G. Bergmann et al. (World Scientific, Singapore, 1998) and references therein Google Scholar
  12. H. Müller, S. Chiow, S. Herrmann, S. Chu, Phys. Rev. Lett. 102, 240403 (2009) CrossRefGoogle Scholar
  13. K. Nordtvedt, gr-qc/0212044 (2002)
  14. A. Peters, C. Keng Yeow, S. Chu, Nature (London) 400, 849 (1999) CrossRefADSGoogle Scholar
  15. A. Peters, K.Y. Chung, S. Chu, Meterologia 38, 25 (2001) CrossRefADSGoogle Scholar
  16. See, e.g. the contributions by B. Schutz T. Damour, Space Sci. Rev. (2009, this issue) Google Scholar
  17. Y. Su et al., Phys. Rev. D 50, 3614 (1994) and references therein CrossRefADSGoogle Scholar
  18. R.F.C. Vessot et al., Phys. Rev. Lett. 45, 2081 (1980) CrossRefADSGoogle Scholar
  19. L. Viola, R. Onofrio, Phys. Rev. D 55, 455 (1997) ADSGoogle Scholar
  20. M. Weitz, T. Heupel, T.W. Hänsch, Phys. Rev. Lett. 77, 2356 (1996) CrossRefADSGoogle Scholar

Copyright information

© The Author(s) 2009

Authors and Affiliations

  1. 1.Max-Planck-Institut für QuantenoptikGarchingGermany
  2. 2.Institut für Angewandte PhysikBonnGermany
  3. 3.Qimonda AGNeubibergGermany

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