610 research outputs found
The two-particle two-slit experiment
Identical two-particle interferometry provides a scenario where interference
and exchange effects manifest at once. We present a detailed calculation of the
detection patterns in the two-particle two-slit experiment by extending
Feynman's Gaussian slit approach to multi-mode states. We show the existence of
two regimes depending on the mode distributions. In one of them we find a novel
behavior for bosons, with detection patterns almost equal to those of
distinguishable particles although the overlapping is large. As a byproduct of
our analysis we conclude that the interaction at the diffraction grating is an
efficient method to increase the initial overlapping. We propose a scheme,
within the reach of present day technology, to experimentally verify our
results
Atomic diffraction by light gratings with very short wavelengths
Lasers with wavelengths of the order of the atomic size are becoming
available. We explore the behavior of light-matter interactions in this
emergent field by considering the atomic Kapitza-Dirac effect. We derive the
diffraction patterns, which are in principle experimentally testable. From a
fundamental point of view, our proposal provides an example of system where the
periodicity of the diffraction grating is comparable to the size of the
diffracted object
Identical two-particle interferometry in diffraction gratings
We study diffraction and interference of indistinguishable particles. We
consider some examples where the wavefunctions and detection probabilities can
be evaluated in an analytical way. The diffraction pattern of a two-particle
system shows notorious differences for the cases of bosons, fermions and
distinguishable particles. In the example of near-field interferometry, the
exchange effects for two-fermion systems lead to the existence of planes at
which the probability of double detection is null. We also discuss the relation
with the approach to systems of identical particles based on correlation
functions. In particular, we shall see that these functions reflect, as in
noise interferometry, the underlying periodic structure of the diffraction
grating
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