Wong-Campos J D, Moses S A, Johnson K G, Monroe C
Joint Quantum Institute, Joint Center for Quantum Information and Computer Science, and Department of Physics, University of Maryland, College Park, Maryland 20742, USA.
Phys Rev Lett. 2017 Dec 8;119(23):230501. doi: 10.1103/PhysRevLett.119.230501.
We demonstrate quantum entanglement of two trapped atomic ion qubits using a sequence of ultrafast laser pulses. Unlike previous demonstrations of entanglement mediated by the Coulomb interaction, this scheme does not require confinement to the Lamb-Dicke regime and can be less sensitive to ambient noise due to its speed. To elucidate the physics of an ultrafast phase gate, we generate a high entanglement rate using just ten pulses, each of ∼20 ps duration, and demonstrate an entangled Bell state with (76±1)% fidelity. These results pave the way for entanglement operations within a large collection of qubits by exciting only local modes of motion.
我们利用一系列超快激光脉冲展示了两个囚禁原子离子量子比特的量子纠缠。与先前由库仑相互作用介导的纠缠演示不同，该方案不需要局限于兰姆-迪克区域，并且由于其速度，对环境噪声的敏感度可能更低。为了阐明超快相位门的物理原理，我们仅使用十个脉冲就产生了高纠缠率，每个脉冲持续时间约为20皮秒，并展示了保真度为(76±1)%的纠缠贝尔态。这些结果为通过仅激发局部运动模式在大量量子比特中进行纠缠操作铺平了道路。
