Temporal-Mode Cluster States

Hans J. Briegel

Takaya Hoshi, Konhi Ichii, Dohoon Lim +12 more

We generate one-dimensional cluster states with temporal-mode durations of 40 ps across over one million qumodes, which enables high-speed and large-scale optical quantum computation.

Herbert F. Fotso, Shuxiang Yang, K. Chen +6 more

Rafael N. Alexander, Shota Yokoyama, Akira Furusawa +1 more

We propose an experimental design for universal continuous-variable quantum computation that incorporates recent innovations in linear-optics-based continuous-variable cluster state generation and cubic-phase gate teleportation. The first ingredient is a protocol for generating the bilayer-square-lattice cluster state (a universal resource state) with temporal modes of light. With this state, measurement-based implementation of Gaussian unitary gates requires only homodyne detection. Second, we describe a measurement device that implements an adaptive cubic-phase gate, up to a random phase-space displacement. It requires a two-step sequence of homodyne measurements and consumes a (non-Gaussian) cubic-phase state.

蒋峰建, 石名俊, 种波 +1 more

Nicolas C. Menicucci

An extensible experimental design for optical continuous-variable cluster states of arbitrary size using four offline (vacuum) squeezers and six beam splitters is presented. This method has all the advantages of a temporal-mode encoding [Phys. Rev. Lett. 104, 250503 (2010)], including finite requirements for coherence and stability even as the computation length increases indefinitely, with none of the difficulty of inline squeezing. The extensibility stems from a construction based on Gaussian projected entangled pair states. The potential for use of this design within a fully fault-tolerant model is discussed.