High-Threshold Fault-Tolerant Quantum Computation with Analog Quantum Error Correction

Abstract

To implement large-scale quantum computation, the Gottesman-Kitaev-Preskill (GKP) qubit has been recognized as an important technological element. However, it is still challenging to experimentally generate the GKP qubit with the required squeezing level for large-scale quantum computation. To reduce this requirement, we develop a method to prevent the squeezing level from decreasing during the construction of the large-scale cluster. We show that our method with the analog quantum error correction can relax the required squeezing level within the reach of the current experimental technology.