||High-Threshold Fault-Tolerant Quantum Computation with Analog Quantum Error Correction
Fukui, Kosuke ,
Tomita, Akihisa ,
Okamoto, AtsushiFujii, Keisuke
2018-05-25 , American Physical Society (APS)
光による量子コンピュータの実現に大きく迫る手法を開発 --従来の100億倍の誤り耐性--. 京都大学プレスリリース. 2018-05-29.
To implement fault-tolerant quantum computation with continuous variables, 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, 14.8 dB, of the existing fault-tolerant quantum computation. To reduce this requirement, we propose a high-threshold fault-tolerant quantum computation with GKP qubits using topologically protected measurement-based quantum computation with the surface code. By harnessing analog information contained in the GKP qubits, we apply analog quantum error correction to the surface code. Furthermore, we develop a method to prevent the squeezing level from decreasing during the construction of the large-scale cluster states for the topologically protected, measurement-based, quantum computation. We numerically show that the required squeezing level can be relaxed to less than 10 dB, which is within the reach of the current experimental technology. Hence, this work can considerably alleviate this experimental requirement and take a step closer to the realization of large-scale quantum computation.