题目：First-principles calculations of AlGaN and ZnO, Quantum teleportation mediated by surface plasmon polariton, and quantum state verification

报告人：蒋新贺 博士后 (南京大学)

时  间：2020年5月27日(周三) 晚上19:30

地  点：腾讯会议 ID：443 179 410密码：052719

摘要：

Using first-principles calculations, we solve the problems of low quantum efficiency in Al-rich AlGaN and p-type doping bottleneck in ZnO semiconductors. The VBM of Al-rich AlGaN can be tuned to be heavy hole band, which has p_x- and p_y-like characteristics and leads to the TE polarized light emission. This improves the light emission efficiency in AlGaN-based LED. By forming the short-period (ZnO)_m/(ZnX)_n (X=S, Se, Te) superlattice, we effectively realize the p-type conductivity in ZnO. In the second part, I will talk about the quantum teleportation mediated by surface plasmon polariton (SPP) and quantum state verification. We experimentally demonstrate the possibility of transmitting the quantum states from single photon to single SPP. The teleportation is characterized with quantum state tomography and quantum process tomography. We obtain the average state fidelity to be 0.889±0.004 and the process fidelity to be 0.820±0.005, which is far more than the classical limit 2/3 and 1/2. This demonstrates the quantum feature of the teleportation process. In addition, we perform quantum state verification for the two-photon polarization-entangled source. Compared with conventional quantum state tomography, the verification strategy requires fewer number of copies of quantum states. We give the number of copies required to achieve the 90% confidence. For the estimation of fidelity, the scaling is close to the Heisenberg limit -1 for the physical parameter estimation. Our method provides a standardized procedure for verifying the quantum devices.

简历：

Xinhe Jiang is currently a Postdoc at School of Physics of Nanjing University. He received his PhD degree in Condensed Matter Physics from Peking University in 2016, and his research focuses on simulations and computations of material properties, quantum information processing with microstructures, foundations of quantum physics and practical quantum information.

联系方式：ygyao@bit.edu.cn

邀请人：姚裕贵 教授

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