Hawking's pediction that black holes, as a consequence of
quantum mechanics, should emit thermal radiation is widely
considered as a milestone of modern theoretical physics.
Despite its conceptual importance, the weak intensity of Hawking
radiation has so far prevented any direct experimental
observation.
Hawking radiation is however not peculiar of gravitational black
holes. It is expected in any system where weavy perturbations
motion experiences some sort of a horizon. Fluids in supersonic
motion are typical examples. Among the systems proposed as
candidates for actual experimental detection of Hawking radiation,
atomic Bose-Einstein condensate appears are the most promising one.
These are among the cleanest systems where quantum physics can be
investigated: the temperature can in fact be made so low that the
behaviour of matter is dominated by the dual particle-wave nature
of its constituens and the quantum dynamics is not masked by
spurious thermal effect.
We Have used the analogy between gravitational systems and
non-homogeneous fluid flows to calculate, using methods borrowed by
quantum field theory in curved space, the density-density
correlation function of an atomic Bose-Einstein condensate in the
presence of an acoustic black hole. The emission of correlated
pairs of phonons by the Hawking effect is expected to result in a
peculiar long-range density correlation . Quantitative estimations
have been provided for realistic experimental configurations.
Hawking's pediction that black holes, as a consequence of
quantum mechanics, should emit thermal radiation is widely
considered as a milestone of modern theoretical physics.
Despite its conceptual importance, the weak intensity of Hawking
radiation has so far prevented any direct experimental
observation.
Hawking radiation is however not peculiar of gravitational black
holes. It is expected in any system where weavy perturbations
motion experiences some sort of a horizon. Fluids in supersonic
motion are typical examples. Among the systems proposed as
candidates for actual experimental detection of Hawking radiation,
atomic Bose-Einstein condensate appears are the most promising one.
These are among the cleanest systems where quantum physics can be
investigated: the temperature can in fact be made so low that the
behaviour of matter is dominated by the dual particle-wave nature
of its constituens and the quantum dynamics is not masked by
spurious thermal effect.
We have used the analogy between gravitational systems and
non-homogeneous fluid flows to calculate, using methods borrowed by
quantum field theory in curved space, the density-density
correlation function of an atomic Bose-Einstein condensate in the
presence of an acoustic black hole. The emission of correlated
pairs of phonons by the Hawking effect is expected to result in a
peculiar long-range density correlation . Quantitative estimations
have been provided for realistic experimental configurations.
