Abstract:

A high quality polarized two-photon entangled state is prepared by using the method of II type parametric down conversion and polarization post selection of nonlinear crystals. The violation of Clauser-Horne-Shimony-Holt(CHSH) and Cavalcanti-Bell (C-B) inequalities to the are experimentally measured in two-photon entangled system, and the values of CHSH, C-B inequalities, 2.64±0.021 and 2.75±0.019, are obtained respectively. The bit flip noise in quantum channels is simulated by linear optical devices, and the robustness of CHSH-type inequality in bit-flipping noise environment is experimentally investigated. Results show that C-B inequality is more robust to noise than CHSH inequality in bit-flipping noise environment, which provides experimental support for further study the application of entanglement in quantum information processing.

Key words: quantum optics; quantum entanglement; nonlocality; parametric down conversion; Clauser-Horne-Shimony-Holt inequality; Cavalcanti-Bell inequality