Scalable Generation of Graph-State Entanglement through Realistic Linear Optics
Timothy P. Bodiya, Luming Duan
Linear optics, combined with practical photon source and single-photon detectors, has provided a powerful tool to test a number of quantum information protocols. In the linear optics implementations, the post-selection technique based on photon detections typically plays a critical role. As one scales up the system, the post-selection technique generally leads to very inefficient (exponential) scaling of the overall efficiency, which limits the implementation to small systems. In the past few years, two approaches have been proposed to circumvent this obstacle for different kinds of quantum information processing. In the first approach, a remarkable proposal, generally referred to as linear optics quantum computation, was first put forward by Knill, Laflamme, and Mil-burn (KLM) [1] and then improved by a number of others. In this approach, one overcomes the scaling problem for linear optics computation through quantum error correction by requiring the efficiencies for the photon source and the detectors to attain a high threshold value [1]. The threshold efficiency has been improved considerably in the past few years, with the most recent estimate about Linear optics, combined with practical photon source and single-photon detectors, has provided a powerful tool to test a number of quantum information protocols. In the linear optics implementations, the post-selection technique based on photon detections typically plays a critical role. As one scales up the system, the post-selection technique generally leads to very inefficient (exponential) scaling of the overall efficiency, which limits the implementation to small systems. In the past few years, two approaches have been proposed to circumvent this obstacle for different kinds of quantum information processing. In the first approach, a remarkable proposal, generally referred to as linear optics quantum computation, was first put forward by Knill, Laflamme, and Mil-burn (KLM) [1] and then improved by a number of others. In this approach, one overcomes the scaling problem for linear optics computation through quantum error correction by requiring the efficiencies for the photon source and the detectors to attain a high threshold value [1]. The threshold efficiency has been improved considerably in the past few years, with the most recent estimate about 99.4%− 99.7% [2]. In the second approach proposed in Ref. [3], one uses linear optics for implementation of scalable quantum communication through the quantum repeater protocol. This approach overcomes the inefficient scaling through the divide-and-conquer method. In this protocol, one does not have a threshold requirement on the source and the detector efficiencies, which allows its implementation with the state-of-the-art photon detectors.
Frontiers in Optics•Jan 1, 2006•3 citations