The Experimental Research Of Quantum Uncertainty Principle And Quantum Coherence

The establishment and development of quantum mechanics not only greatly pro-mote the development of human's science,technology and civilization,but also subvert people's perception of the physical world.Classic physics tells us that the real world is continuous and deterministic,which means that given the initial state of a system,according to classical mechanics,we can know its state of motion at the arbitrary mo-ment accurately.However,the physical world explained by the quantum mechanics is discontinuous and uncertain.Quantum superposition principle tells us that physical systems can be not only in the one of eigenstates of an observable,but also in the form of arbitrary superpositon of its eigenstates,and the measurement will cause the system to collapse to an eigenstate with a probability.For a pair of incompatible observables,we are limited to get their precise outcomes simultaneously by quantum uncertainty princi-ple,which means that the more accurate the measurement outcomes of one observable is,the greater the uncertainty of the measurement outcomes of the other observable will be.Quantum uncertainty principle and quantum coherence originating from quantum state superposition principle are two of the most fundamental characteristics of quantum mechanics discriminating from classical physics.Both of them have a long history of research,and are still hot research topics of physics with their important applications in quantum information science,quantum metrology,etc.Due to the advantages such as relatively weak interaction with the environment and high fidelity in the preparation of entangled states,linear optical system is one of the most mature and convenient exper-imental platforms referring to the studies of several qubit systems' quantum simulation and quantum correlation.The main works of this thesis includes two aspects:1.As the research of uncertainty principle moving along,various forms of uncertain-ty relations are proposed,and finding the tighter lower bounds of the uncertainty relations has always been one of research directions of interest.Based on the linear optical system,we investigate a new type of uncertain relations in exper-iment,and we also have carried out some corresponding numerical simulations.Our results show that the fine-graining method may help to obtain a tighter lower bound of uncertainty relations.2.Since the resource theory framework of coherence has been proposed in recent years,people have increasingly interests in studying coherence as a quantum re-source and the quantification of coherence has always attracted researchers' atten-tions.Based on a linear optical system,we experimentally investigate a trade-off relation between the coherence measures quantified by relative entropy of coher-ence in two non-commuting reference bases.Our result shows that the sum of quantum coherence under these bases is bounded in a region defined by its lower bound and upper bound.Furthermore,we find an interesting phenomenon that the lower bound of the trade-off relation that is restricted by the uncertainty rela-tion for coherence,would not be tighten with the presence of entanglement.Our results may contribute to further study of the uncertainty principle and quantum coherence.