Advanced quantum technologies require scalable and controllable quantum resources 1 , 2 . Gaussian states of multimode light, such as squeezed states and cluster states, are scalable quantum systems 3… Click to show full abstract
Advanced quantum technologies require scalable and controllable quantum resources 1 , 2 . Gaussian states of multimode light, such as squeezed states and cluster states, are scalable quantum systems 3 – 5 , which can be generated on demand. However, non-Gaussian features are indispensable in many quantum protocols, especially to reach a quantum computational advantage 6 . Embodying non-Gaussianity in a multimode quantum state remains a challenge as non-Gaussian operations generally cannot maintain coherence among multiple modes. Here, we generate non-Gaussian quantum states of a multimode light field by removing a single photon in a mode-selective manner from a Gaussian state 7 . To highlight the potential for continuous-variable quantum technologies, we first demonstrated the capability to generate negativity of the Wigner function in a controlled mode. Subsequently, we explored the interplay between non-Gaussianity and quantum entanglement and verify a theoretical prediction 8 about the propagation of non-Gaussianity along the nodes of photon-subtracted cluster states. Our results demonstrate large-scale non-Gaussianity with great flexibility along with an ensured compatibility with quantum information protocols. This range of features makes our approach ideal to explore the physics of non-Gaussian entanglement 9 , 10 and to develop quantum protocols, which range across quantum computing 11 , 12 , entanglement distillation 13 and quantum simulations 14 . Continuous-variables quantum information processing requires non-Gaussian states and operations. The generation of non-Gaussian quantum states of a multimode field is now reported through a mode-selective photon-subtraction scheme
               
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