Bayerbach Matthias J, D'Aurelio Simone E, van Loock Peter, Barz Stefanie
Institute for Functional Matter and Quantum Technologies, University of Stuttgart, 70569 Stuttgart, Germany.
Center for Integrated Quantum Science and Technology (IQST), University of Stuttgart, 70569 Stuttgart, Germany.
Sci Adv. 2023 Aug 9;9(32):eadf4080. doi: 10.1126/sciadv.adf4080.
Bell-state projections serve as a fundamental basis for most quantum communication and computing protocols today. However, with current Bell-state measurement schemes based on linear optics, only two of four Bell states can be identified, which means that the maximum success probability of this vital step cannot exceed 50%. Here, we experimentally demonstrate a scheme that amends the original measurement with additional modes in the form of ancillary photons, which leads to a more complex measurement pattern, and ultimately a higher success probability of 62.5%. Experimentally, we achieve a success probability of (57.9 ± 1.4)%, a substantial improvement over the conventional scheme. With the possibility of extending the protocol to a larger number of ancillary photons, our work paves the way toward more efficient realizations of quantum technologies based on Bell-state measurements.
贝尔态投影是当今大多数量子通信和计算协议的基本基础。然而，基于线性光学的当前贝尔态测量方案只能识别四个贝尔态中的两个，这意味着这一关键步骤的最大成功概率不能超过50%。在此，我们通过实验证明了一种方案，该方案通过以辅助光子的形式添加额外模式来修正原始测量，这会导致更复杂的测量模式，并最终实现62.5%的更高成功概率。在实验中，我们实现了(57.9±1.4)%的成功概率，相比传统方案有了显著提高。随着将该协议扩展到更多辅助光子的可能性，我们的工作为基于贝尔态测量的更高效量子技术实现铺平了道路。
