Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080, USA.
Phys Rev Lett. 2010 Jul 16;105(3):030407. doi: 10.1103/PhysRevLett.105.030407.
Quantum teleportation faces increasingly demanding requirements for transmitting large or even entangled systems. However, knowledge of the state to be transmitted eases its reconstruction, resulting in a protocol known as remote state preparation. A number of experimental demonstrations to date have been restricted to single-qubit systems. We report the remote preparation of two-qubit "hybrid" entangled states, including a family of vector-polarization beams. Our single-photon states are encoded in the photon spin and orbital angular momentum. We reconstruct the states by spin-orbit state tomography and transverse polarization tomography. The high fidelities achieved for the vector-polarization states opens the door to optimal coupling of down-converted photons to other physical systems, such as an atom, as required for scalable quantum networks, or plasmons in photonic nanostructures.
量子隐形传态对于传输大型甚至纠缠系统的要求越来越高。然而,对要传输的状态的了解使其重建变得容易,从而产生了一种称为远程状态制备的协议。迄今为止,许多实验演示都仅限于单量子比特系统。我们报告了两量子比特“混合”纠缠态的远程制备,包括一系列矢量偏振光束。我们的单光子态编码在光子自旋和轨道角动量中。我们通过自旋轨道态层析成像和横向偏振层析成像来重建态。矢量偏振态实现的高保真度为下转换光子与其他物理系统(如原子)的最佳耦合打开了大门,这是可扩展量子网络或光子纳米结构中的等离子体所必需的。