Anderson Delocalization in Strongly Coupled Disordered Non-Hermitian Chains

Disorder and non-Hermitian effects together can upend how waves localize. In a 1D disordered chain, the non-Hermitian skin effect (NHSE) can induce Anderson delocalization, defying the usual rule that disorder in low dimensions always localizes states. While weak disorder leaves the NHSE intact, strong disorder restores Anderson localization. Here, we study a surprising twist: coupling a strongly disordered Hatano-Nelson chain to a disordered Hermitian chain with their disorder antisymmetrically correlated. Strikingly, once the interchain coupling exceeds a threshold, the system undergoes Anderson delocalization irrespective of disorder strength, reinstating the NHSE with no Hermitian counterpart. This transition arises from the interplay of nonreciprocal hopping, interchain coupling, and engineered disorder correlations, and is captured by a real-space winding number. To confirm this, we build an electrical-circuit analog and directly observe the reemergent NHSE via voltage measurements. Our Letter uncovers unexplored and experimentally accessible physics at the crossroads of non-Hermiticity and disorder.