Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.
Phys Rev Lett. 2011 May 27;106(21):210503. doi: 10.1103/PhysRevLett.106.210503. Epub 2011 May 26.
Entanglement between stationary systems at remote locations is a key resource for quantum networks. We report on the experimental generation of remote entanglement between a single atom inside an optical cavity and a Bose-Einstein condensate (BEC). To produce this, a single photon is created in the atom-cavity system, thereby generating atom-photon entanglement. The photon is transported to the BEC and converted into a collective excitation in the BEC, thus establishing matter-matter entanglement. After a variable delay, this entanglement is converted into photon-photon entanglement. The matter-matter entanglement lifetime of 100 μs exceeds the photon duration by 2 orders of magnitude. The total fidelity of all concatenated operations is 95%. This hybrid system opens up promising perspectives in the field of quantum information.
远程静止系统之间的纠缠是量子网络的关键资源。我们报告了在光学腔中的单个原子和玻色-爱因斯坦凝聚体（BEC）之间产生远程纠缠的实验。为此，在原子-腔系统中产生单个光子，从而产生原子-光子纠缠。光子被传输到 BEC 并转换为 BEC 中的集体激发，从而建立物质-物质纠缠。经过可变延迟，这种纠缠被转换为光子-光子纠缠。物质-物质纠缠的寿命为 100 μs，比光子持续时间长两个数量级。所有级联操作的总保真度为 95％。这种混合系统为量子信息领域开辟了广阔的前景。
