Enlarging the Schrödinger cat state through the superposition of two kitten states in coupled waveguides
Nuo Wang, Xinchen Zhang, Qi Liu +3 more
The optical Schrödinger’s cat is highly anticipated for its potential to realize fault-tolerant quantum computing and quantum metrology. To attain a good performance in these processes, the amplitude of cat states is desired to be as high as possible. Here, we demonstrate the enlargement of a cat state through the superposition of two kitten states in coupled waveguides. Under reasonable superposition coefficients, the interference between two nearby coherent state components in the initial kittens will produce a coherent-like state with a larger amplitude, enabling the creation of larger cat-like states. Based on the above mechanism, we theoretically demonstrate the superposition of two kittens in coupled waveguides through conditional measurements. In an appropriate propagation length, a cat state, whose amplitude is enlarged beyond α 0 2 + β 0 2 , is achieved with high fidelity and a high success probability when the amplitudes of input kittens are α 0 and i β 0 , respectively. The mechanism we propose has the potential to be realized in other systems, and it could be extended to amplify other macroscopic quantum states. The physical realization based on coupled waveguides demonstrates the ability to efficiently amplify cat states and is expected to become a competitive approach for on-chip cat state preparation.
Journal of the Optical Society of America B•Mar 3, 2025•0 citations