Controlling topological phases is a central goal in quantum materials and related fields, enabling applications such as robust transport and programmable edge states. Here, we uncover a mechanism by which local on-site impurities act as knobs to decompose global topological properties in discrete steps. In non-Hermitian lattices with spectral winding topology, we show that impurities can sequentially reduce the winding number, which is directly manifested as a stepwise decomposition of quantized plateaus in the steady-state response. Based on this principle, we further develop a scheme that sequentially induces topological edge states under impurity control, in a class of Hermitian topological systems constructed by doubling non-Hermitian ones. Such decomposition also applies to higher-order topology in two or higher dimensions. Our findings reveal a general framework to tune global topological properties with local distortions, providing a versatile route toward impurity-controlled reconfigurable topological phenomena across diverse physical platforms.

Close

PrevNext

View figure in article

• Impurities
• Topological phases of matter
• Lattices
• Non-Hermitian systems
• Tight-binding model