Heo Jino, Hong Changho, Choi Seong-Gon, Hong Jong-Phil
College of Electrical and Computer Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Republic of Korea.
Base Technology Division, National Security Research Institute, P.O. Box 1, Yuseong, Daejeon, 34188, Republic of Korea.
Sci Rep. 2019 Jul 12;9(1):10151. doi: 10.1038/s41598-019-46231-7.
We represent an optical scheme using cross-Kerr nonlinearities (XKNLs) and quantum dot (QD) within a single-sided optical cavity (QD-cavity system) to generate three-photon entangled W state containing entanglement against loss of one photon of them. To generate W state (three-photon) with robust entanglement against loss of one photon, we utilize effects of optical nonlinearities in XKNLs (as quantum controlled operations) and QD-cavity system (as a parity operation) with linearly optical devices. In our scheme, the nonlinear (XKNL) gate consists of weak XKNLs, quantum bus beams, and photon-number-resolving measurement to realize controlled-unitary gate between two photons while another nonlinear (QD) gate employs interactions of photons and an electron of QD confined within a single-sided optical cavity for implementation of parity gate. Subsequently, for the efficiency and experimental feasibility of our scheme generating W state, we analyze the immunity of the controlled-unitary gate using XKNLs against decoherence effect and reliable performance of parity gate using QD-cavity system.
我们提出了一种光学方案，该方案在单侧光学腔（量子点 - 腔系统）中利用交叉克尔非线性（XKNLs）和量子点（QD）来生成三光子纠缠W态，其中包含对其中一个光子损失的纠缠抗性。为了生成对一个光子损失具有强纠缠抗性的W态（三光子），我们利用XKNLs中的光学非线性效应（作为量子控制操作）以及量子点 - 腔系统中的光学非线性效应（作为宇称操作），并结合线性光学器件。在我们的方案中，非线性（XKNL）门由弱XKNLs、量子总线光束和光子数分辨测量组成，以实现两个光子之间的受控酉门，而另一个非线性（量子点）门利用光子与限制在单侧光学腔内的量子点中的电子之间的相互作用来实现宇称门。随后，为了我们生成W态方案的效率和实验可行性，我们分析了使用XKNLs的受控酉门对退相干效应的抗性以及使用量子点 - 腔系统的宇称门的可靠性能。
