Four-State Modulation in Middle of a Quantum Channel for Continuous-Variable Quantum Key Distribution Protocol with Noiseless Linear Amplifier

We characterize a modified continuous-variable quantum key distribution(CV-QKD)protocol with four states in the middle of a quantum channel.In this protocol,two noiseless linear amplifiers(NLAs) are inserted before each detector of the two parts,Alice and Bob,with the purpose of increasing the secret key rate and the maximum transmission distance.We present the performance anal.ysis of the new four-state CV-QKD protocol over a Gaussian lossy and noisy channel.The simulation results show that the NLAs with a reasonable gain g can effectively enhance the secret key rate as well as the maximum transmission distance,which is generally satisfied in practice.     

多任务学习在分子性质预测中的对比研究（英文）

随着深度学习的快速发展,相关算法被广泛应用于量子化学计算领域以实现高效的分子设计及性质研究.其中,多任务学习方法通过挖掘分子性质之间的关系可以同时预测多个分子属性,然而此类研究目前较为有限.本文采用硬参数共享结构与损失函数加权方法来实现多任务分子性质预测.通过对比单任务基准与各类多任务模型在不同分子属性集上的性能,展示了多属性预测精度强烈依赖于属性间的关系,当关联变复杂时,硬参数共享可以提高预测精度.此外,恰当的损失函数加权方法有利于实现更均衡的多目标优化,使预测更准确.进一步的实验展示了多任务学习模型的计算效率优势及其在训练数据量受限时的预测性能优势.     

Expected H →μ+μ-measurement precision with e+e-→Z(q■)H production at the CEPC

A search for the dimuon decay of the Standard Model Higgs boson is performed using Monte Carlo simulated events to mimic data corresponding to an integrated luminosity of 5.6 ab^-1 collected with the Circular Electron-Positron Collider detector in e⁺e^-collisions at■GeV.This study investigates thee⁺e^-→ZH,Z→q■,H→μ⁺μ^-process,and the expected significance considering only the statistical uncertainty in the data for a backgro...