We consider a device which can be programmed using coherent states of light to approximate a given projective measurement on an input coherent state. We provide and discuss three practical implementations of this programmable projective measurement device with linear optics, involving only balanced beam splitters and single photon threshold detectors. The three schemes optimally approximate any projective measurement onto a program coherent state in a non-destructive fashion. We further extend these to the case where there are no assumptions on the input state. In this setting, we show that our scheme enables an efficient verification of an unbounded untrusted source with only local coherent states, balanced beam splitters, and threshold detectors. Exploiting the link between programmable measurements and generalised swap test, we show as a direct application that our schemes provide an asymptotically quadratic improvement in existing quantum fingerprinting protocol to approximate the Euclidean distance between two unit vectors.
A single programmable photonic circuit for universal quantum measurements
University of Science and Technology of China（中国科学技术大学）；Hefei National Laboratory（合肥国家实验室）；Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area（粤港澳大湾区量子科学中心）
Programmable Coherent Memory Kernels for Quantum Reservoir Computing in Waveguide QED
Quantum Advanced Research Center, QuARC-CSIC（量子先进研究中心）；Instituto de Física Fundamental, IFF-CSIC（基础物理研究所）；Department of Physics, Shanghai University（上海大学物理系）；Instituto de Ciencia de Materiales de Madrid ICMM-CSIC（马德里材料科学研究所）
Programmable coherent site-selective spin control in rotating Penning-trap ion crystals
School of Physics, The University of Sydney（悉尼大学物理学院）；Department of Physics, Indian Institute of Technology Madras（马德拉斯理工学院物理系）；Center for Quantum Information, Communication and Computing, Indian Institute of Technology Madras（马德拉斯理工学院量子信息、通信与计算中心）；Sydney Nano Institute, The University of Sydney（悉尼大学悉尼纳米研究所）
Interplay of Confinement and Localization in a Programmable Rydberg Atom Chain
Jülich Supercomputing Centre, Forschungszentrum Jülich（于利希超级计算中心，于利希研究中心）；RWTH Aachen University（亚琛工业大学）；Department of Computer Science, University of Cologne（科隆大学计算机科学系）；Institute for Advanced Simulation, Forschungszentrum Jülich（于利希研究中心先进模拟研究所）；Jožef Stefan Institute（约瑟夫·斯蒂芬研究所）；CENN Nanocenter（CENN纳米中心）
Programmable quantum simulation of anharmonic dynamics
University of Sydney（悉尼大学）；School of Physics, University of Sydney（悉尼大学物理学院）；School of Chemistry, University of Sydney（悉尼大学化学学院）；University of Sydney Nano Institute（悉尼大学纳米研究所）
The Hong Kong University of Science and Technology (Guangzhou)（香港科技大学（广州））；Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area（粤港澳大湾区量子科学中心）
Quantum synchronization and chimera states in a programmable quantum many-body system
RIKEN Center for Emergent Matter Science (CEMS)（RIKEN 涌现物质科学中心）；RIKEN Center for Quantum Computing (RQC)（RIKEN 量子计算中心）；RIKEN Center for Computational Science (R-CCS)（RIKEN 计算科学中心）；RIKEN Cluster for Pioneering Research (CPR)（RIKEN 先锋研究集群）
Instruction-Set Architecture for Programmable NV-Center Quantum Repeater Nodes
University of Pisa（比萨大学）；Institute for Informatics and Telematics (IIT), National Research Council (CNR)（意大利国家研究委员会信息学与遥测研究所）；Technische Universität Dresden（德累斯顿工业大学）
Entropy Transport in Programmable Quantum Junctions
Peter Grünberg Institute for Quantum Computing Analytics (PGI-12), Forschungszentrum Jülich（于利希研究中心）；Institute for Quantum Information, RWTH Aachen University（亚琛工业大学）；Kavli Institute of Nanoscience, Delft University of Technology（代尔夫特理工大学）
Transverse quantum-state characterization of programmable electron optics
Friedrich-Alexander-Universität Erlangen-Nürnberg（弗里德里希·亚历山大埃尔朗根-纽伦堡大学）；CNR Istituto Nanoscienze（意大利国家研究委员会纳米科学研究所）；CNR Istituto per lo Studio dei Materiali Nanostrutturati（意大利国家研究委员会纳米结构材料研究所）；Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich（于利希研究中心恩斯特·鲁斯卡电子显微镜与光谱学中心）
