Loss-induced universal one-way transport in periodically driven systems

In this Letter, we show that a periodically driven Aubry-Andr\'e-Harper model with imbalanced onsite gain/loss supports universal one-way transport that is immune to impurities and independent of initial excitations. We reveal the underlying mechanism that the periodic driving gives rise to the non-Hermitian skin effect in the effective Floquet Hamiltonian, thereby causing universal non-reciprocal transport. Additionally, we probe the Lyapunov exponent under long-time dynamics as a signature of the Floquet emergent non-Hermitian skin effect. Our results provide a feasible and controllable way to realize universal one-way transport that is easily accessible to experiments.