In this paper, a new proposal was presented to probabilistically transmit an unknown quantum state from a sender to a remote receiver with the aid of a controller when the non-maximally entangled state is only available for the sender. Meanwhile, the whole successful probability and classical communication of this scheme for controlled teleportation are calculated. The concrete processes of our proposal are elaborated in detail. This scheme would be used to expand the research range of quantum controlled teleportation.
In order to improve the detection efficiency in QKD system, this paper has put forward a new quantum key distribution scheme based on the single photon frequency up-conversion detection technology and decoy-state BB84 protocol. A long wavelength pump light is adopted in single photon detector (SPD) to avoid the noise caused by spontaneous parametric down conversion (SPDC), thus an overall 28% detection efficiency is achieved which is five times of 4.5% in conventional InGaAs-based detectors. Moreover, the propagating distances has reached 90km and 150km with weak coherent pulse (WCP) and decoy weak coherent pulse (DWCP) respectively, which is 1.3 times and 1.05 times of the conventional InGaAs-based detectors of 70km and 140km.