Generation And Applications Of Several Types Of Entangled States On Photonic Chips

Quantum entanglement is a unique property of quantum system and lies at the heart of many new technologies and applications in the emerging quantum information science.Multi-particle entangled states reveal the mystery of quantum mechanics and are the basis of quantum computing,quantum communication,quantum metrology and lithography,and is the key resource for quantum information system to be large-scale and practical.In recent years,photonic system has been greatly developed as an important research and implementation carrier because of its advantages such as high transmission rate,long coherence time and varieties degrees of freedom.Photonic systems are divided into bulk optics and integrated optics.Coding methods in bulk optics are various and mature,polarization is one of the most commonly used modes,which can support long-distance free space transmission.However,while propagating on the chip,the time deviation of different polarization cannot be negligible,leading to the quantum state distorted.Therefore,finding more appropriate and diverse degrees of freedom for chips has become an urgent problem to be solved.Moreover,compared with bulk optics,the integrated photonic system has strong scalability,high stability,and can be programmed and reconfigurable to complete various quantum information processing tasks.Based on above questions,this thesis focuses on how to realize different types of photon coding methods on photonic chips.Then,based on these different coding methods,generation of several entangled states and corresponding application design are realized.The completed work of this thesis includes the following three aspects:1.Design an on-chip generation scheme of maximal entangled states based on path encoding.In this scheme,two spectral uncorrelated degenerate quantum sources and an interference photonic circuit are integrated into the same photonic chip.By controlling the interference photonic circuit,the heralded three-photon and four-photon path entangled NOON states are obtained.Then by using our NOON states,we demonstrate the super-sensitivity and super-resolution in the field of quantum precision measurement and sensing.2.Design an on-chip tunable quantum entanglement source based on frequency encoding.In this scheme,the generation of two non-degenerate photon pairs and the interference photonic circuit are integrated.By tuning the on-chip phase,the statistical properties of bosons and fermions are simulated.Furthermore,we designed quantum walk characteristics with multi-particles of different statistical properties and show its property in graph search algorithm.3.Design an on-chip time-bin coded entanglement state generation scheme.Various existing modes and technologies of quantum key distribution are studied.The improvement and alternative schemes of on-chip integrated transceiver/transmitter as well as measurement devices are proposed,which improves the performance of communication such as distance without using repeaters and enhances the stability of communication.