8,756 research outputs found
Hindrance of heavy-ion fusion due to nuclear incompressibility
We propose a new mechanism to explain the unexpected steep falloff of fusion
cross sections at energies far below the Coulomb barrier. The saturation
properties of nuclear matter are causing a hindrance to large overlap of the
reacting nuclei and consequently a sensitive change of the nuclear potential
inside the barrier. We report in this letter a good agreement with the data of
coupled-channels calculation for the {64}Ni+{64}Ni combination using the
double-folding potential with M3Y-Reid effective N-N forces supplemented with a
repulsive core that reproduces the nuclear incompressibility for total overlap.Comment: 4 pages, 3 figure
Multiphoton path entanglement by non-local bunching
Multiphoton path entanglement is created without applying post-selection, by
manipulating the state of stimulated parametric down-conversion. A specific
measurement on one of the two output spatial modes leads to the non-local
bunching of the photons of the other mode, forming the desired multiphoton path
entangled state. We present experimental results for the case of a heralded
two-photon path entangled state and show how to extend this scheme to higher
photon numbers.Comment: 4 pages, 5 figures, published versio
Projection of two biphoton qutrits onto a maximally entangled state
Bell state measurements, in which two quantum bits are projected onto a
maximally entangled state, are an essential component of quantum information
science. We propose and experimentally demonstrate the projection of two
quantum systems with three states (qutrits) onto a generalized maximally
entangled state. Each qutrit is represented by the polarization of a pair of
indistinguishable photons - a biphoton. The projection is a joint measurement
on both biphotons using standard linear optics elements. This demonstration
enables the realization of quantum information protocols with qutrits, such as
teleportation and entanglement swapping.Comment: 4 pages, 3 figures, published versio
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