Anderson localization transition in a robust PT-symmetric phase of a generalized Aubry-André model

We study a generalized Aubry-Andr\'e model that obeys PT symmetry. We observe a robust PT-symmetric phase with respect to system size and disorder strength, where all eigenvalues are real despite the Hamiltonian being non-Hermitian. This robust PT-symmetric phase can support an Anderson localization transition, giving a rich phase diagram as a result of the interplay between disorder and PT symmetry. Our model provides a perfect platform to study disorder-driven localization phenomena in a PT-symmetric system.