Experimental Study Of Quantum Simulation And Free Space Quantum Communication

As an inter-discipline,quantum information has been mainly applied in communication and computing.In communication,the world is making effort to move forward to satellite-constellation-based global quantum network of security.Because of the imperious need for processing massive information in the information era,more and more governments and high-technology companies invest huge amount of money to develop quantum computer.The development of quantum information is closely linked to people's future life.On one hand,as with the completion of security transmission through quantum communication network,the national defense security and people's privacy can get forceful guarantee.On the other hand,the successful implementation of quantum computer can change many fields,such as the life-style and medical level of people.This research contributes to quantum communication and quantum computing.One experiment in this research is quantum key distribution in daylight.This experiment is necessary to construct the worldwide satellite network.The worldwide satellite network is made up of several satellites,and it is not possible that every satellite is located in the Earth shadow zone.In order to achieve the quantum communication among satellites,the successful implementation of quantum key distribution in the daytime is necessary.Thus,this research contributes to quantum communication.In the field of quantum computing,this research conduct two important work,which are experimental ten-photon entanglement and simulation of anyonic topological path.Multi-photon entanglement is always the core resources in quantum computing,the number of entangled photons directly determines the quantum computing capability.Thus,photon,as the most easy-controllable qubit carrier,has captured much attention in research.This research firstly achieved the ten-photon entanglement in experiment,which contributes much for the development of quantum computer.Meanwhile,having more qubit resources make it possible that more complex quantum simulating experiment can be conducted.The experiment of the robustness of anyonic braiding is conducted under this condition.Because of the topological property,anyons can achieve fault-tolerant quantum computation in hardware,which is called topological quantum error correction.As everyone knows that the capability of error correction determines the efficiency of quantum computing,and the inherent property of anyons make it to be a popular choice of quantum computer.Thus,our research laid a foundation for the development of quantum computer.Except for the application field,this research contributes to the nature of quantum correlations.Quantum pigeonhole effect is a kind of exploration for quantum effect.In this experiment,we showed a new quantum effect,which is that when three particles are putted into two boxes,no two particles can be found in the same box.The quantum effect changed our basic notions of quantum physics---the notion of severability,of correlations,and of interactions,which contributes to the understanding of quantum mechanics.