Aolita Leandro, Gogolin Christian, Kliesch Martin, Eisert Jens
Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin, Germany.
Instituto de Física, Universidade Federal do Rio de Janeiro, P. O. Box 68528, Rio de Janeiro 21941-972, Brazil.
Nat Commun. 2015 Nov 18;6:8498. doi: 10.1038/ncomms9498.
Quantum technologies promise a variety of exciting applications. Even though impressive progress has been achieved recently, a major bottleneck currently is the lack of practical certification techniques. The challenge consists of ensuring that classically intractable quantum devices perform as expected. Here we present an experimentally friendly and reliable certification tool for photonic quantum technologies: an efficient certification test for experimental preparations of multimode pure Gaussian states, pure non-Gaussian states generated by linear-optical circuits with Fock-basis states of constant boson number as inputs, and pure states generated from the latter class by post-selecting with Fock-basis measurements on ancillary modes. Only classical computing capabilities and homodyne or hetorodyne detection are required. Minimal assumptions are made on the noise or experimental capabilities of the preparation. The method constitutes a step forward in many-body quantum certification, which is ultimately about testing quantum mechanics at large scales.
量子技术有望带来各种令人兴奋的应用。尽管最近已经取得了令人瞩目的进展，但目前一个主要瓶颈是缺乏实用的认证技术。挑战在于确保传统上难以处理的量子设备按预期运行。在此，我们为光子量子技术提出一种实验友好且可靠的认证工具：一种针对多模纯高斯态、以恒定玻色子数的福克基态作为输入通过线性光学电路生成的纯非高斯态以及通过对辅助模式进行福克基测量后选择从后一类生成的纯态的实验制备的高效认证测试。仅需要经典计算能力以及零差或外差检测。对制备的噪声或实验能力做出的假设极少。该方法在多体量子认证方面向前迈进了一步，而多体量子认证最终是关于在大尺度上测试量子力学。
