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Science
; 275(5306): 1638-40, 1997 Mar 14.
Artículo
en Inglés
| MEDLINE
| ID: mdl-9054356
RESUMEN
Femtosecond laser pulses and coherent two-phonon Raman scattering were used to excite KTaO3 into a squeezed state, nearly periodic in time, in which the variance of the atomic displacements dips below the standard quantum limit for half of a cycle. This nonclassical state involves a continuum of transverse acoustic modes that leads to oscillations in the refractive index associated with the frequency of a van Hove singularity in the phonon density of states.
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