Abstract
Superadditivity relations characterize the distributions of coherence in multipartite quantum systems. In this work, we investigate the superadditivity relations related to the l₁-norm of coherence C_l₁ in multiqubit quantum systems. Tighter superadditivity inequalities based on the α-th (α 1) power of l₁-norm of coherence are presented for multiqubit states under certain conditions, which include the existing results as special cases. These superadditivity relations give rise to finer characterization of the coherence distributions among the subsystems of a multipartite system. A detailed example is presented.