A new way to construct topological invariants of non-Hermitian systems with the non-Hermitian skin effect<xref rid="cpb_29_1_010302fn1" ref-type="fn">*</xref><fn id="cpb_29_1_010302fn1"><label>*</label><p>Project supported by Hebei Provincial Natural Science Foundation of China (Grant Nos. A2012203174 and A2015203387) and the National Natural Science Foundation of China (Grant Nos. 10974169 and 11304270).</p></fn>

A new way to construct topological invariants of non-Hermitian systems with the non-Hermitian skin effect**

Project supported by Hebei Provincial Natural Science Foundation of China (Grant Nos. A2012203174 and A2015203387) and the National Natural Science Foundation of China (Grant Nos. 10974169 and 11304270).

Liu J S, Han Y Z, Liu C S^†

(a) Non-Hermitian SSH model. The yellow-dashed box indicates the unit cell. (b) Coupled SSH model with alternating t₁, t₂ hoppings and a non-Hermitian t₃ ± γ/2 hopping. The imbalance hopping between the adjacent unit cells (the black-dotted boxes) leads to the non-Hermitian skin effect disappearing.