Abstract: Methods are disclosed for generating, manipulating, and controlling non-Gaussian quantum states in continuous variable cluster quantum states usable for quantum computing. Some methods can be used to generate, transport, and enlarge Schrödinger-Cat states embedded in the CV cluster quantum state. Some methods can be used to transform Schrödinger-Cat states embedded in the CV quantum cluster state to grid states (such as Gottesman-Kitaev-Preskill states) and enlarge the grid states. In certain embodiments, some of the methods may be used to generate and control non-Gaussian states in macronode cluster quantum states such as cluster states comprising two-mode macronodes.

Abstract: Systems and methods are disclosed for generating cluster quantum states usable for quantum computing. An example system can generate a plurality of qumodes. The plurality of qumodes can include at least two successive qumodes in frequency domain, wherein a frequency spacing between two successive qumodes is equal to a free-spectral range of an optical frequency comb. The plurality of qumodes can include a plurality of bipartite entangled states. A cluster quantum state can be generated by modulating a phase of a portion of the optical fields associated with the plurality of qumodes received from the optical frequency comb, at one or more modulation frequencies. In some embodiments, each of the one or more modulation frequencies can be equal to an integral multiple of the free-spectral-range. In certain embodiments, a property of a cluster graph (such as a dimension of the cluster graph) associated with the cluster quantum state can be controlled by adjusting one or more modulation frequencies.