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Title: Measurement of the Temperature Dependence of the Casimir-Polder Force

Abstract

We report on the first measurement of a temperature dependence of the Casimir-Polder force. This measurement was obtained by positioning a nearly pure {sup 87}Rb Bose-Einstein condensate a few microns from a dielectric substrate and exciting its dipole oscillation. Changes in the collective oscillation frequency of the magnetically trapped atoms result from spatial variations in the surface-atom force. In our experiment, the dielectric substrate is heated up to 605 K, while the surrounding environment is kept near room temperature (310 K). The effect of the Casimir-Polder force is measured to be nearly 3 times larger for a 605 K substrate than for a room-temperature substrate, showing a clear temperature dependence in agreement with theory.

Authors:
; ;  [1]; ;  [2];  [2];  [3]
  1. JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440, USA, and Department of Physics, University of Colorado, Boulder, Colorado 80309-0390 (United States)
  2. Dipartimento di Fisica, Universita di Trento and CNR-INFM BEC Center, Via Sommarive 14, I-38050 Povo, Trento (Italy)
  3. (Russian Federation)
Publication Date:
OSTI Identifier:
20955445
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 98; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevLett.98.063201; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; BOSE-EINSTEIN CONDENSATION; DIELECTRIC MATERIALS; DIPOLES; OSCILLATIONS; RUBIDIUM 87; SUBSTRATES; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 0400-1000 K

Citation Formats

Obrecht, J. M., Wild, R. J., Cornell, E. A., Antezza, M., Stringari, S., Pitaevskii, L. P., and Kapitza Institute for Physical Problems, ulitza Kosygina 2, 119334 Moscow. Measurement of the Temperature Dependence of the Casimir-Polder Force. United States: N. p., 2007. Web. doi:10.1103/PHYSREVLETT.98.063201.
Obrecht, J. M., Wild, R. J., Cornell, E. A., Antezza, M., Stringari, S., Pitaevskii, L. P., & Kapitza Institute for Physical Problems, ulitza Kosygina 2, 119334 Moscow. Measurement of the Temperature Dependence of the Casimir-Polder Force. United States. doi:10.1103/PHYSREVLETT.98.063201.
Obrecht, J. M., Wild, R. J., Cornell, E. A., Antezza, M., Stringari, S., Pitaevskii, L. P., and Kapitza Institute for Physical Problems, ulitza Kosygina 2, 119334 Moscow. Fri . "Measurement of the Temperature Dependence of the Casimir-Polder Force". United States. doi:10.1103/PHYSREVLETT.98.063201.
@article{osti_20955445,
title = {Measurement of the Temperature Dependence of the Casimir-Polder Force},
author = {Obrecht, J. M. and Wild, R. J. and Cornell, E. A. and Antezza, M. and Stringari, S. and Pitaevskii, L. P. and Kapitza Institute for Physical Problems, ulitza Kosygina 2, 119334 Moscow},
abstractNote = {We report on the first measurement of a temperature dependence of the Casimir-Polder force. This measurement was obtained by positioning a nearly pure {sup 87}Rb Bose-Einstein condensate a few microns from a dielectric substrate and exciting its dipole oscillation. Changes in the collective oscillation frequency of the magnetically trapped atoms result from spatial variations in the surface-atom force. In our experiment, the dielectric substrate is heated up to 605 K, while the surrounding environment is kept near room temperature (310 K). The effect of the Casimir-Polder force is measured to be nearly 3 times larger for a 605 K substrate than for a room-temperature substrate, showing a clear temperature dependence in agreement with theory.},
doi = {10.1103/PHYSREVLETT.98.063201},
journal = {Physical Review Letters},
number = 6,
volume = 98,
place = {United States},
year = {Fri Feb 09 00:00:00 EST 2007},
month = {Fri Feb 09 00:00:00 EST 2007}
}
  • We have performed a measurement of the Casimir-Polder force using a magnetically trapped {sup 87}Rb Bose-Einstein condensate. By detecting perturbations of the frequency of center-of-mass oscillations of the condensate perpendicular to the surface, we are able to detect this force at a distance {approx}5 {mu}m, significantly farther than has been previously achieved, and at a precision approaching that needed to detect the modification due to thermal radiation. Additionally, this technique provides a limit for the presence of non-Newtonian gravity forces in the {approx}1 {mu}m range.
  • We show that Rabi oscillations of a degenerate fermionic or bosonic gas trapped in a double-well potential can be exploited for the interferometric measurement of external forces at micrometer length scales. The Rabi interferometer is less sensitive but easier to implement than the Mach-Zehnder, since it does not require dynamical beam-splitting or recombination processes. As an application we propose a measurement of the Casimir-Polder force acting between the atoms and a dielectric surface. We find that even if the interferometer is fed with a coherent state of relatively small number of atoms, and in the presence of realistic experimental noise,more » the force might be measured with a sensitivity sufficient to discriminate between thermal and zero-temperature regimes of the Casimir-Polder potential. Higher sensitivities can be reached with bosonic spin squeezed states.« less
  • We analyze the magnetic dipole contribution to atom-surface dispersion forces. Unlike its electrical counterpart, it involves small transition frequencies that are comparable to thermal energy scales. A significant temperature dependence is found near surfaces with a nonzero dc conductivity, leading to a strong suppression of the dispersion force at T>0. We use thermal response theory for the surface material and discuss both normal metals and superconductors. The asymptotes of the free energy of interaction and of the entropy are calculated analytically over a large range of distances. Near a superconductor, the onset of dissipation at the phase transition strongly changesmore » the interaction, including a discontinuous entropy. We discuss the similarities with the Casimir interaction between two surfaces and suggest that precision measurements of the atom-surface interaction may shed light upon open questions around the temperature dependence of dispersion forces between lossy media.« less
  • We calculate the effect of the interaction between an optically active material and a Bose-Einstein condensate on the collective oscillations of the condensate. We provide explicit expressions for the frequency shift of the center-of-mass oscillation in terms of the potential generated by the substrate and of the density profile of the gas. The form of the potential is discussed in detail and various regimes (van der Waals-London, Casimir-Polder, and thermal regimes) are identified as a function of the distance of atoms from the surface. Numerical results for the frequency shifts are given for the case of a sapphire dielectric substratemore » interacting with a harmonically trapped condensate of {sup 87}Rb atoms. We find that at distances of 4-8 {mu}m, where thermal effects become visible, the relative frequency shifts produced by the substrate are of the order 10{sup -4} and hence accessible experimentally. The effects of nonlinearities due to the finite amplitude of the oscillation are explicitly discussed. Predictions are also given for the radial breathing mode.« less
  • No abstract prepared.