Using a Kerr interaction for GKP magic state preparation

• URL: http://arxiv.org/abs/2507.09684v1
• Date: Sun, 13 Jul 2025 15:43:43 GMT
• Title: Using a Kerr interaction for GKP magic state preparation
• Authors: Jérémie Boudreault, Ross Shillito, Jean-Baptiste Bertrand, Baptiste Royer,
• Abstract summary: We study a non-Gaussian unitary mediated by a Kerr interaction which realizes a logical gate $sqrtH_L$ for square GKP codes.<n>This gate does not directly involve an auxiliary qubit and is compatible with finite energy constraints on the code.<n>We propose a circuit QED implementation to operate the Kerr interaction.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Magic state distillation and injection is a promising strategy towards universal fault tolerant quantum computation, especially in architectures based on the bosonic Gottesman-Kitaev-Preskill (GKP) codes where non-Clifford gates remain challenging to implement. Here we address GKP magic state preparation by studying a non-Gaussian unitary mediated by a Kerr interaction which realizes a logical gate $\sqrt{H}_L$ for square GKP codes. This gate does not directly involve an auxiliary qubit and is compatible with finite energy constraints on the code. Fidelity can be further enhanced using the small-Big-small (SBS) error correction protocol and post-selection, making the scheme robust against a single photon loss event. We finally propose a circuit QED implementation to operate the Kerr interaction.

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