Dense coding in photonic quantum communication with enhanced information capacity

Citation
K. Shimizu et al., Dense coding in photonic quantum communication with enhanced information capacity, PHYS REV A, 59(2), 1999, pp. 1092-1097
Citations number
15
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW A
ISSN journal
10502947 → ACNP
Volume
59
Issue
2
Year of publication
1999
Pages
1092 - 1097
Database
ISI
SICI code
1050-2947(199902)59:2<1092:DCIPQC>2.0.ZU;2-0
Abstract
We propose a scheme for enhancing the information capacity to more than 2 b its in dense coding quantum communication that involves transmitting a pola rization entangled twin photon and a subsequent joint measurement with a Be ll-state analyzer. Although direct modulation of the timing position and op tical frequency of the photon play no role in dense coding quantum communic ation, we show that the frequency-dependent phase correlation of polarizati on entangled twin photons can be used for this enhancement if photon twins are generated through optical parametric down-conversion. With our proposed Bell-state analyzer containing a nonlinear optical gate, the capacity can be enhanced from the reported 2 bits to 3 bits by the local operation of a frequency-dependent phase shift on the transmitted photon. [S1050-2947(99)0 4802-7].