Li Sai, Ni Zhongchu, Zhang Libo, Cai Yanyan, Mai Jiasheng, Wen Shengcheng, Zheng Pan, Deng Xiaowei, Liu Song, Xu Yuan, Yu Dapeng
Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
International Quantum Academy, Shenzhen 518048, China.
Phys Rev Lett. 2024 May 17;132(20):203602. doi: 10.1103/PhysRevLett.132.203602.
Fock states with a well-defined number of photons in an oscillator have shown a wide range of applications in quantum information science. Nonetheless, their usefulness has been marred by single and multiphoton losses due to unavoidable environment-induced dissipation. Though several dissipation engineering methods have been developed to counteract the leading single-photon-loss error, averting multiple-photon losses remains elusive. Here, we experimentally demonstrate a dissipation engineering method that autonomously stabilizes multiphoton Fock states against losses of multiple photons using a cascaded selective photon-addition operation in a superconducting quantum circuit. Through measuring the photon-number populations and Wigner tomography of the oscillator states, we observe a prolonged preservation of nonclassical Wigner negativities for the stabilized Fock states |N⟩ with N=1, 2, 3 for a duration of about 10 ms. Furthermore, the dissipation engineering method demonstrated here also facilitates the implementation of a nonunitary operation for resetting a binomially encoded logical qubit. These results highlight potential applications in error-correctable quantum information processing against multiple-photon-loss errors.
振荡器中具有明确光子数的福克态在量子信息科学中已展现出广泛应用。尽管如此，由于不可避免的环境诱导耗散导致的单光子和多光子损失，使其效用大打折扣。虽然已经开发了几种耗散工程方法来抵消主要的单光子损失误差，但避免多光子损失仍然难以实现。在此，我们通过实验展示了一种耗散工程方法，该方法在超导量子电路中使用级联选择性光子添加操作，自主稳定多光子福克态以防止多光子损失。通过测量振荡器态的光子数分布和维格纳断层扫描，我们观察到对于稳定的福克态|N⟩（N = 1、2、3），非经典维格纳负性在约10毫秒的持续时间内得到了延长的保留。此外，这里展示的耗散工程方法还便于实现用于重置二项式编码逻辑量子比特的非酉操作。这些结果突出了在针对多光子损失误差的可纠错量子信息处理中的潜在应用。
