Heo Jino, Kang Min-Sung, Hong Chang Ho, Hong Jong-Phil, Choi Seong-Gon
College of Electrical and Computer Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Republic of Korea.
Center for Quantum Information, Korea Institute of Science and Technology (KIST), Seoul, 136-791, Republic of Korea.
Sci Rep. 2018 Sep 14;8(1):13843. doi: 10.1038/s41598-018-32137-3.
We present a scheme to encode quantum information (single logical qubit information) into three-photon decoherence-free states, which can conserve quantum information from collective decoherence, via nonlinearly optical gates (using cross-Kerr nonlinearities: XKNLs) and linearly optical devices. For the preparation of the decoherence-free state, the nonlinearly optical gates (multi-photon gates) consist of weak XKNLs, quantum bus (qubus) beams, and photon-number-resolving (PNR) measurement. Then, by using a linearly optical device, quantum information can be encoded on three-photon decoherence-free state prepared. Subsequently, by our analysis, we show that the nonlinearly optical gates using XKNLs, qubus beams, and PNR measurement are robust against the decoherence effect (photon loss and dephasing) in optical fibers. Consequently, our scheme can be experimentally implemented to efficiently generate three-photon decoherence-free state encoded quantum information, in practice.
我们提出了一种将量子信息（单个逻辑量子比特信息）编码到三光子无退相干态的方案，该方案可通过非线性光学门（利用交叉克尔非线性：XKNLs）和线性光学器件来保护量子信息免受集体退相干的影响。为了制备无退相干态，非线性光学门（多光子门）由弱XKNLs、量子总线（qubus）光束和光子数分辨（PNR）测量组成。然后，通过使用线性光学器件，可以将量子信息编码到所制备的三光子无退相干态上。随后，通过我们的分析表明，利用XKNLs、qubus光束和PNR测量的非线性光学门对光纤中的退相干效应（光子损失和相位衰减）具有鲁棒性。因此，在实际中我们的方案可以通过实验实现以高效地生成编码量子信息的三光子无退相干态。
