星载量子纠缠源关键技术与发展应用

发布时间：2018-04-03 21:05

本文选题：量子信息　切入点：量子计算　出处：《中国科学技术大学》2017年博士论文

【摘要】：量子信息是量子物理和信息科学交叉结合所产生的新学科,具有经典信息学无法比拟的优势和前景,同时也为重新认识和理解量子理论提供了新的途径,在近些年迅速发展为学术界的重要研究热点之一。非定域性是量子物理最具争议的重要特性。自从贝尔不等式提出以来,在各种条件下检验量子纠缠非定域关联的努力就从未停止。作为迈向量子力学非定域性终极检验的重要一步,将量子纠缠源搭载在人造卫星上,使得纠缠光子对能被分别发往地面上相距超过千公里的两个地点,验证量子纠缠态在星地大尺度下是否依然能保持其非定域关联特性。本人参与研制世界上首个星载量子纠缠源。该量子纠缠源需要能承受卫星发射时的强烈震动、在轨期间恶劣的辐射和温度环境以及长期无人维护的考验,同时满足对重量、体积的苛刻要求。为此,我们发展了一套可靠的光机集成方案,配合高精度装校和高效率单模光纤耦合技术,将传统的基于Sagnac干涉环的参量下转换量子纠缠源集成化、工程化。最终,该量子纠缠源每秒可产生高达8 ×116对纠缠光子对,保真度超过95%。该量子纠缠源作为"墨子"号量子科学实验卫星的主要载荷之一,于2016年8月16日发射入轨。在轨测试数据表明该量子纠缠源性能正常,可以开展德令哈-丽江地面站、德令哈-南山地面站之间的千公里级量子纠缠分发实验。通过进一步改进发展星载量子纠缠源的装校工艺,我们将熔融石英材质的光学器件直接粘接在熔融石英基底上以实现具有极高稳定性和极低损耗的干涉仪阵列,并用于量子点单光子源的玻色采样演示中。量子点单光子源具有很高的亮度和很好的单光子性,但是独立源之间的干涉仍然困难。为了得到玻色采样需要的全同多光子光源,我们使用泡克尔盒阵列和长度精确调节的延时光纤将一个单光子脉冲序列切为若干个同步的脉冲序列。由于目前泡克尔盒的重复频率远低于单光子脉冲的重复频率,脉冲序列按组切分。最终,我们演示了 5光子/9模式的玻色采样,采样率是先前其他研究组最好结果的24,000倍,超越第一台电子计算机(ENIAC)1～2个量级。我们为玻色采样研制的泡克尔盒阵列也被应用在演示全新的量子密钥分发协议(RRDPS-QKD)中,其对误码率的容忍最高可达50%;改进的粘接工艺可用于制造更稳定和紧凑的光学设备,为未来量子星座天地组网做技术储备。
[Abstract]:Quantum information is a new subject produced by the combination of quantum physics and information science. It has the advantages and prospects that classical informatics cannot compare, and it also provides a new way to reunderstand and understand quantum theory.In recent years, it has become one of the important research hotspots in academic circles.Nonlocality is one of the most controversial and important properties of quantum physics.Since Bell's inequality was put forward, the efforts to test the delocalization of quantum entanglement under various conditions have never stopped.As an important step towards the ultimate test of nonlocality in quantum mechanics, the quantum entangled source is mounted on an artificial satellite, so that the entangled photon pairs can be sent to two locations on the ground more than 1,000 kilometers apart.It is verified whether the quantum entangled state can maintain its nonlocal correlation at large scale.I participated in the development of the world's first spaceborne quantum entanglement source.The quantum entangled source should be able to withstand the strong vibration during satellite launch, the harsh radiation and temperature environment during orbit and the long-term unmaintained test, and meet the harsh requirements of weight and volume at the same time.For this reason, we have developed a reliable optical machine integration scheme, which integrates the traditional parametric down-conversion quantum entanglement source based on Sagnac interferometer and works with high-precision calibration and high-efficiency single-mode fiber coupling technology.Finally, the quantum entanglement source can produce up to 8 脳 116 pairs of entangled photon pairs per second, and the fidelity exceeds 95 pairs.As one of the main payloads of Mozi, the quantum entanglement source was launched into orbit on August 16, 2016.The in-orbit data show that the quantum entanglement source is normal and can be used for the quantum entanglement distribution experiments between Delingha-Lijiang earth station and Delingha-Nanshan earth station.By further improving the calibration process of spaceborne quantum entanglement sources, we directly bonded the fused quartz optical devices onto the fused quartz substrate to achieve a very high stability and very low loss interferometer array.It is also used in the boson sampling demonstration of quantum dot single photon source.Quantum dot single photon source has high brightness and good single photon property, but the interference between independent sources is still difficult.In order to obtain the fully identical multiphoton light source for boson sampling, we use the bubble Kerr cell array and the precisely adjusted delay fiber to cut a single photon pulse sequence into several synchronous pulse sequences.Because the repetition rate of the bubble Kerr cell is much lower than that of the single photon pulse, the pulse sequence is segmented into groups.Finally, we demonstrated Bose sampling in the 5 photon / 9 mode at a sampling rate of 24000 times that of the previous best results of other research groups, exceeding the first computer, ENIAC, by 1 to 2 orders of magnitude.The bubble cell array we developed for Bose sampling has also been used to demonstrate a new quantum key distribution protocol RRDPS-QKD, which can tolerate up to 50 bit error rates; the improved bonding process can be used to make more stable and compact optical devices.For the future of the quantum constellation of heaven and earth network to do the technical reserve.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：V447;O413

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