Laboratory of Quantum Engineering of Light, South Ural State University (SUSU), Chelyabinsk, Russia.
Institute of Physics, Kazan Federal University (KFU), Kazan, Russia.
Sci Rep. 2023 Mar 9;13(1):3965. doi: 10.1038/s41598-023-30218-6.
We present an algorithm of quantum engineering of large-amplitude [Formula: see text] high-fidelity [Formula: see text] even/odd Schrödinger cat states (SCSs) using a single mode squeezed vacuum (SMSV) state as resource. Set of [Formula: see text] beam splitters (BSs) with arbitrary transmittance and reflectance coefficients sequentially following each other acts as a hub that redirects a multiphoton state into the measuring modes simultaneously measured by photon number resolving (PNR) detectors. We show that the multiphoton state splitting guarantees significant increase of the success probability of the SCSs generator compared to its implementation in a single PNR detector version and imposes less requirements on ideal PNR detectors. We prove that the fidelity of the output SCSs and its success probability are in conflict with each other (which can be quantified) in a scheme with ineffective PNR detectors, especially when subtracting large (say, [Formula: see text]) number of photons, i.e., increasing the fidelity to perfect values leads to a sharp decrease in the success probability. In general, the strategy of subtracting up to [Formula: see text] photons from initial SMSV in setup with two BSs is acceptable for achieving sufficiently high values of the fidelity and success probability at the output of the generator of the SCSs of amplitude [Formula: see text] with two inefficient PNR detectors.
我们提出了一种使用单模压缩真空（SMSV）态作为资源来工程化大振幅[Formula: see text]高保真度[Formula: see text]奇偶 Schrödinger 猫态（SCS）的量子算法。一组具有任意透射率和反射率系数的[Formula: see text]分束器（BS）依次跟随彼此，充当一个集线器，将多光子态同时引导到由光子数分辨（PNR）探测器同时测量的测量模式中。我们表明，与在单个 PNR 探测器版本中的实现相比，多光子态分裂保证了 SCS 发生器的成功概率显著增加，并且对理想 PNR 探测器的要求较低。我们证明，在具有非有效 PNR 探测器的方案中，输出 SCS 的保真度和成功概率是相互冲突的（可以量化），特别是在减去大量（例如，[Formula: see text]）光子时，即，将保真度提高到完美值会导致成功概率急剧下降。一般来说，在具有两个 BS 的设置中从初始 SMSV 减去多达[Formula: see text]光子的策略对于在具有两个非有效 PNR 探测器的 SCS 发生器的输出端实现足够高的保真度和成功概率是可接受的。
