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Decaying isotope in BEC?

  1. Aug 17, 2009 #1
    So this is a very novice but sincere question. I've just done a bit of reading about Bose-Einstein condensates, and the question that I immediately had was, What happens if one creates a BEC out of an isotope which is subject to radioactive decay? Would the atoms all necessarily remain in the same state? Or decay in lockstep? Is it even possible to create a BEC with such a material?

    Thanks -
  2. jcsd
  3. Aug 18, 2009 #2
    At a first glance, I'd expect the answer to be a competition between energies: you gain energy by decaying, but lose by taking atoms out of the BEC. I would imagine that for all decays with a realistic lifetime, the energy involved greatly out-weighs the energy to pay for reducing the condensate.
  4. Aug 18, 2009 #3
    Thanks for your reply. I believe you are correct regarding the competition between energies.

    If a BEC were to be achieved, wouldn't all the atoms in the condensate then share the same quantum state? If so, wouldn't they then all have to decay either at once or not at all? Maybe if some of them decay prior to reaching the BEC then it precludes them from ever doing so with undecayed atoms? In general is it possible to make a BEC with a heterogeneous condensate?
  5. Aug 18, 2009 #4

    intuitively, i can not see anything potentially interesting about a bec of decaying isotopes.

    let us do not talk about nuclear physics, but just atomic physics

    assume that all the atoms are in the electronic excited state, so that they also will decay by emitting photons.

    the atoms couple to the EM waves in the universe

    If the radius of the bec is much smaller than the wavelength of the photon, then they will decay collectively, this effect is called Dicke superradiance

    if the radius of the bec is much larger than the wavelength of the photon, then intuitively, i think there is nothing of a nature of collectiveness.

    For the nuclear reaction, say, the wavelength of the gamma rays is just orders smaller than the radius of the bec, and i guess there is nothing special.
  6. Aug 18, 2009 #5
    i think you can have a look of the mossbauer effect
  7. Aug 18, 2009 #6
  8. Aug 18, 2009 #7


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    A very similar situation to a decaying isotope is the BEC of 2d microcavity exciton-polaritons. These are basically quasiparticles composed of some excitonic and some photonic content confined in a cavity and constantly leak out of the cavity due to the photonic content.

    The landmark paper in this area is "Bose–Einstein condensation of exciton polaritons" by J. Kasprzak et al., Nature 443, 409-414. There are also many follow-up papers on the physics of nonequilibrium BECs.
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