Options
Constant depth fault-tolerant Clifford circuits for multi-qubit large block codes
Citation
Zheng, Y.-C., Lai, C.-Y., Brun, T. A., & Kwek, L.-C. (2020). Constant depth fault-tolerant Clifford circuits for multi-qubit large block codes. Quantum Science and Technology, 5(4), Article 045007. https://doi.org/10.1088/2058-9565/aba34d
Abstract
Fault-tolerant quantum computation (FTQC) schemes using large block codes that encode k > 1 qubits in n physical qubits can potentially reduce the resource overhead to a great extent because of their high encoding rate. However, the fault-tolerant (FT) logical operations for the encoded qubits are difficult to find and implement, which usually takes not only a very large resource overhead but also long in situ computation time. In this paper, we focus on Calderbank–Shor–Steane [[n, k, d]] (CSS) codes and their logical FT Clifford circuits. We show that the depth of an arbitrary logical Clifford circuit can be implemented fault-tolerantly in O(1) steps in situ via either Knill or Steane syndrome measurement circuit, with the qualified ancilla states efficiently prepared. Particularly, for those codes satisfying k/n ~ Θ(1), the resource scaling for Clifford circuits implementation on the logical level can be the same as on the physical level up to a constant, which is independent of code distance d. With a suitable pipeline to produce ancilla states, our scheme requires only a modest resource cost in physical qubits, physical gates, and computation time for very large scale FTQC.
Date Issued
2020
Publisher
IOP Publishing
Journal
Quantum Science and Technology
Grant ID
IG14-LR001
Ministry of Science and Technology, Taiwan (Grant no. MOST108-2636-E-009-004)
NSF Grant no. CCF-1421078
NSF Grant no. MPS-1719778
Funding Agency
National Research Foundation of Singapore
Ministry of Education (MOE), Singapore
Yale-NUS College
Ministry of Science and Technology, Taiwan
IBM Einstein Fellowship at the Institute for Advanced Study
Ministry of Science and Technology, Taiwan