Einstein Locality and the Quantum Mechanical Long-Distance Effects

C. S. Unnikrishnan

The long-standing puzzle of the nonlocal Einstein-Podolsky-Rosen correlations is resolved. The correct quantum mechanical correlations arise for the case of entangled particles when strict locality is assumed for the probability amplitudes instead of locality for probabilities. Locality of amplitudes implies that measurement on one particle does not collapse the companion particle to a definite state.

David Böhm, Basil J. Hiley

Dengke Qi, Xiangyu Wang, Jiayu Ma +4 more

Quantum key distribution relying on the principles of quantum mechanics enables two parties to produce a shared random secret key, thereby ensuring the security of data transmission. Continuous variable quantum key distribution (CV-QKD) is widely applied because it can be well combined with standard telecommunication technology. Compared to CV-QKD with a transmitting local oscillator, the proposal of CV-QKD with a local local oscillator overcomes the limitation that local oscillator will attenuate as transmission distance increases, providing new possibilities in long-distance transmission. However, challenges still persist in practical long-distance transmission, including data sampling and recovery under low signal-to-noise ratio conditions. In order to better recover data and reduce the additional excess noise, we propose the least squares fitting algorithm to get more accurate sampling data and complete more accurate phase compensation.Herein, we demonstrate the long-distance local local oscillator CV-QKD experiment which have considered the effect of finite-size block over 120 km of standard optical fiber with high efficient real-time post-processing. The results not only verify the good performance of the system over long distance, but also paves the way for large-scale quantum secure communications in the future.

Xiaohui Jiang

1.The key or origin of EPR paradox lies in the fact that there is something with the background knowledge which is accepted as correct.Through ideal experiment and EPR argument,Einstein and others have found that the metatheoretical non-local hypothesis behind quantum mechanics seems to conflict with the theory of relativity.2.Experiment test of Bell's inequality is a kind of crucial experiment.3.The metaphors of Neurath's repairing the ship during voyage and Popper's swamp have given a vivid explanation that scientific theories may have a relatively reliable base of experience.Accordingly,the background knowledge that could be wrong is qualified to be the relatively reliable logic base of crucial experiment.4.Einstein is not in defending realism and non-act-a-distance.However,the holism of quantum mechanics and long-range correlation cannot be ignored,for they will have profound implication which calls for further study.

Francisco Flores