Non-Clifford gate on optical qubits by nonlinear feedforward

In a continuous-variable optical system, the Gottesman-Kitaev-Preskill (GKP) qubit is promising candidate for fault-tolerant quantum computation. To implement non-Clifford operations on GKP qubits, non-Gaussian are required. this context, implementation of cubic phase gate by combining nonlinear feedforward with ancillary states has been widely researched. Recently, however, it was pointed out that not most suitable qubits. paper, we show can achieve linear qubits high fidelity applying originally developed and using GKP-encoded state. Our paper shows versatility technique---important