Bonn 2001 – wissenschaftliches Programm
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GR: Gravitation und Relativitätstheorie
GR 2: Experimentelle Tests
GR 2.3: Fachvortrag
Montag, 26. März 2001, 18:30–18:45, VII
Observation of quantum states in gravity — •A. Westphal1, H. Abele1, S. Baessler1, H. Boerner2, A. Gagarski3, V. Nesvizhevsky2, G. Petrov3, A. Petukhov2, F. Ruess1 und A. Strelkov4 — 1Physikalisches Institut, Philosophenweg 12, 69120 Heidelberg — 2Institut Laue-Langevin, B.P. 156, 38042 Grenoble, France — 3PNPI, Gatchina, Russia — 4JINR, Dubna, Russia
We observe quantum states in a gravitational cavity, when ultra cold neutrons are trapped above the Fermi potential of a horizontal mirror. In this case one would expect bound states which are formed by Airy functions. The subtlety of our quantum system arises from the fact, that quantum states in gravity have energies far below even MOT energies. Our neutrons originating from a thermal neutron source must have a transversal energy of several peV corresponding to classical turning point heights of several 10 µm. In our experiment about 0.3 neutrons per second reached the detector passing a 80 µm wide one-dimensional gravitational wave guide formed by the bottom mirror, an absorber above and the earth’s gravitational field in between. Results show a strong deviation compared with the classical expectations at small widths. They are in agreement with quantum mechanical predictions. So far, tests for deviations from classical gravity at small distances have been done with torsion pendula down to 200 µm. Our experiment with an elementary particle has the ability to test gravity in a regime of 15 µm to 150 µm. String theoreticians have derived short distance modifications of gravity via large extra dimensions or Yukawa couplings.