On Galois hulls of linear codes and new entanglement-assisted quantum error-correcting codes

TL;DR

This paper investigates Galois hulls of linear codes, characterizes their properties, constructs new classes of Galois self-orthogonal codes, and applies these findings to develop new entanglement-assisted quantum error-correcting codes with improved parameters.

Contribution

It introduces new conditions for Galois self-orthogonal codes, provides explicit construction methods, and applies these to generate novel quantum error-correcting codes with enhanced features.

Findings

Symmetry in Galois hull dimensions identified

New Galois self-orthogonal code constructions proposed

Many new entanglement-assisted quantum codes with good parameters developed

Abstract

The Galois hull of a linear code is the intersection of itself and its Galois dual code, which has aroused the interest of researchers in these years. In this paper, we study Galois hulls of linear codes. Firstly, the symmetry of the dimensions of Galois hulls of linear codes is found. Some new necessary and sufficient conditions for linear codes being Galois self-orthogonal codes, Galois self-dual codes, and Galois linear complementary dual codes are characterized. Then, we propose explicit methods to construct Galois self-orthogonal codes of larger length from given Galois self-orthogonal codes. As an application, linear codes of larger length with Galois hulls of arbitrary dimensions are further derived. Focusing on the Hermitian inner product, two new classes of Hermitian self-orthogonal maximum distance separable (MDS) codes are also constructed. Finally, applying all the results to the construction of entanglement-assisted quantum error-correcting codes (EAQECCs), many new $q$-ary or $\sqrt{q}$-ary EAQECCs and MDS EAQECCs with rates greater than or equal to $\frac{1}{2}$ and positive net rates can be obtained. Moreover, the minimum distance of many $\sqrt{q}$-ary MDS EAQECCs of length $n>\sqrt{q}+1$ is greater than or equal to $\lceil \frac{\sqrt{q}}{2} \rceil$.