33 research outputs found
Cloning quantum entanglement in arbitrary dimensions
We have found a quantum cloning machine that optimally duplicates the
entanglement of a pair of -dimensional quantum systems. It maximizes the
entanglement of formation contained in the two copies of any
maximally-entangled input state, while preserving the separability of
unentangled input states. Moreover, it cannot increase the entanglement of
formation of all isotropic states. For large , the entanglement of formation
of each clone tends to one half the entanglement of the input state, which
corresponds to a classical behavior. Finally, we investigate a local
entanglement cloner, which yields entangled clones with one fourth the input
entanglement in the large- limit.Comment: 6 pages, 3 figure
A proposal of a UCN experiment to check an earthquake waves model
Elastic waves with transverse polarization inside incidence plane can create
longitudinal surface wave (LSW) after reflection from a free surface. At a
critical incidence angle this LSW accumulates energy density, which can be
orders of magnitude higher than energy density of the incident transverse wave.
A specially arranged vessel for storage of ultracold neutrons (UCN) can be used
to verify this effect.Comment: 8 pages 3 figures added a paragraph on vibrations along surface at
critical angl
Those wonderful elastic waves
We consider in a simple and general way elastic waves in isotropic and
anisotropic media, their polarization, speeds, reflection from interfaces with
mode conversion, and surface waves. Reflection of quasi transverse waves in
anisotropic media from a free surface is shown to be characterized by three
critical angles.Comment: 11 Figures 26 page