RESEARCH REPORTS FROM A.D. GAZAZYAN AND CO-AUTHORS PROVIDE NEW INSIGHTS INTO PHYSICS

Science Letter
July 7, 2009

"The possibility of storage of quantum information with photons is
studied in the case of resonant transitions via many close lying
exciton levels in a solid with impurity Lambda-atoms. The upper
levels of the impurity atom form resonant Fano states, similar to the
autoionization atomic states, due to the configuration interaction
with the continuum of the exciton band," scientists writing in the
European Physical Journal D report (see also Physics).

"In this case slowing of light pulses is shown to be realistic, in the
presence of the control field, down to the group velocity much lower
than that in vacuum. The possibility of storage and reconstruction of
a quantum pulse is studied in the case of the instantaneous switching
on/off of the control field. It is shown that the signal quantum pulse
cannot be stored undistorted for differing values of Fano parameters
and for non-zero two-photon detuning and decay rate between the lower
levels (decoherence)," wrote A.D. Gazazyan and colleagues.

The researchers concluded: "However, for small difference of the Fano
parameters and for small values of the two-photon detuning and the
decoherence there is no distortion in the case where the length of
the pulse is much longer than the linear absorption ( amplification)
length, so the shape and quantum state of the light pulse can be
restored.."

Gazazyan and colleagues published their study in European Physical
Journal D (Quantum memory for photons in case of many close
lying exciton resonances in solids. European Physical Journal D,
2009;53(2):243-251).

Additional information can be obtained by contacting A.D. Gazazyan,
NAS Armenia, Institute Physics Research, Ashtarak 0203 2, Armenia.

The publisher of the European Physical Journal D can be contacted at:
Springer, 233 Spring St., New York, NY 10013, USA.