Fault-Tolerant Quantum LDPC Encoders

TL;DR

This paper introduces fault-tolerant quantum LDPC encoders that leverage qubit grouping and preshared entanglement to enable transversal implementation, reducing error propagation in quantum error correction.

Contribution

It presents a novel encoder design for quantum LDPC codes that enhances fault tolerance through qubit grouping and entanglement, applicable to both entanglement-assisted and unassisted codes.

Findings

Reduces error propagation in quantum LDPC encoding

Enables transversal implementation with multi-qubit gates

Applicable to both entanglement-assisted and unassisted codes

Abstract

We propose fault-tolerant encoders for quantum low-density parity check (LDPC) codes. By grouping qubits within a quantum code over contiguous blocks and applying preshared entanglement across these blocks, we show how transversal implementation can be realized. The proposed encoder reduces the error propagation while using multi-qubit gates and is applicable for both entanglement-unassisted and entanglement-assisted quantum LDPC codes.