Takahashi Hiroki, Wakui Kentaro, Suzuki Shigenari, Takeoka Masahiro, Hayasaka Kazuhiro, Furusawa Akira, Sasaki Masahide
National Institute of Information and Communications Technology, 4-2-1 Nukui-kitamachi, Koganei, Tokyo 184-8795, Japan.
Phys Rev Lett. 2008 Dec 5;101(23):233605. doi: 10.1103/PhysRevLett.101.233605. Epub 2008 Dec 4.
We propose and demonstrate a novel method to generate a large-amplitude coherent-state superposition (CSS) via ancilla-assisted photon subtraction. The ancillary mode induces quantum interference of indistinguishable processes in an extended space, widening the controllability of quantum superposition at the conditional output. We demonstrate this by a simple time-separated two-photon subtraction from continuous wave squeezed light. We observe the largest CSS of traveling light ever reported without correcting any imperfections, which will enable various quantum information applications with CSS states.
我们提出并展示了一种通过辅助光子减法生成大振幅相干态叠加（CSS）的新方法。辅助模式在扩展空间中诱导不可区分过程的量子干涉，拓宽了条件输出处量子叠加的可控性。我们通过从连续波压缩光中进行简单的时间分离双光子减法来证明这一点。我们观察到了有史以来报道的无需校正任何缺陷的最大行波光CSS，这将使各种基于CSS态的量子信息应用成为可能。
